The thermal structure of Triton's atmosphere - Pre-Voyager models

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, James B.; Zent, Aaron P.; Cruikshank, Dale P.; Courtin, Regis

1989-01-01

Spectral data from earth observations have indicated the presence of N2 and CH4 on Triton. This paper outlines the use of the 1-D radiative-convective model developed for Titan to calculate the current pressure of N2 and CH4 on Triton. The production of haze material is obtained by scaling down from the Titan value. Results and predictions for the Voyager Triton encounter are as follows: A N2-CH4 atmosphere on Triton is thermodynamically self consistent and would have a surface pressure of approximately 50 millibar; due to the chemically produced haze, Triton has a hot atmosphere with a temperature of approximately 130 K; Triton's troposphere is a region of saturation of the major constituent of the atmosphere, N2.

Foil Electron Multiplier

DOEpatents

Funsten, Herbert O.; Baldonado, Juan R.; Dors, Eric E.; Harper, Ronnie W.; Skoug, Ruth M.

2006-03-28

An apparatus for electron multiplication by transmission that is designed with at least one foil having a front side for receiving incident particles and a back side for transmitting secondary electrons that are produced from the incident particles transiting through the foil. The foil thickness enables the incident particles to travel through the foil and continue on to an anode or to a next foil in series with the first foil. The foil, or foils, and anode are contained within a supporting structure that is attached within an evacuated enclosure. An electrical power supply is connected to the foil, or foils, and the anode to provide an electrical field gradient effective to accelerate negatively charged incident particles and the generated secondary electrons through the foil, or foils, to the anode for collection.

Complex Geologic History of Triton

NASA Technical Reports Server (NTRS)

1989-01-01

Part of the complex geologic history of icy Triton, Neptune's largest satellite, is shown in this Voyager 2 photo, which has a resolution of 900 meters (2,700 feet) per picture element. The photo was received as part of a Triton-mapping sequence between 3:30 and 5:30 a.m. (PDT). This view is about 500 kilometers (300 miles) across. It encompasses two depressions, possibly old impact basins, that have been extensively modified by flooding, melting, faulting, and collapse. Several episodes of filling and partial removal of material appear to have occurred. The rough area in the middle of the bottom depression probably marks the most recent eruption of material. Only a few impact craters dot the area, which shows the dominance of internally driven geologic processes on Triton.

JPL manages the Voyager project for NASA's Office of Space Science.

Distribution and nature of UV absorbers on Triton's surface

NASA Technical Reports Server (NTRS)

Stern, S. Alan

1995-01-01

Substantial evidence suggests that a UV spectrally Absorbing Material (UV-SAM) exists on Triton's surface. This evidence is found in the positive slope in Triton's spectrum from the UV to the near-IR, and the increasing contrast in Triton's light curve in the blue and UV. Although it is now widely-thought that UV-SAMs exist on Triton, little is known about their distribution and spectral properties. The goal of this NDAP Project is to determine the spatial distribution and geological context of the UV-SaM material. We hope to determine if UV-SAMs on Triton are correlated with geologic wind streaks, craters, calderas, geomorphic/topographic units, regions containing (or lacking) volatile frosts, or some other process (e.g., magnetospheric interactions). Once the location and distribution of UV-SAMs has been determined, further constraints on their composition cable made by analyzing the spectrographic data set. To accomplish these goals, various data sets will be used, including Voyager 2 UV and visible images of Triton's surface, IUE and HST spectra of Triton, and a geologic map of the surface based on voyager 2 and spectrophotometric data. The results of this research will be published in the planetary science literature.

Distribution and nature of UV absorbers on Triton's surface

NASA Technical Reports Server (NTRS)

Stern, S. Alan

1994-01-01

Substantial evidence suggests that a UV Spectrally Absorbing Material (UV-SAM) exists on Triton's surface. This evidence is found in the positive slope in Triton's spectrum from the UV to the near-IR, and the increasing contrast in Triton's light curve in the blue and UV. Although it is now widely-thought that UV-SAM's exist on Triton, little is known about their distribution and spectral properties. The goal of this NDAP Project is to determine the spatial distribution and geological context of the UV-SAM material. We hope to determine if UV-SAM's on Triton are correlated with geologic wind streaks, craters, calderas, geomorphic/topographic units, regions containing (or lacking) volatile frosts, or some other process (e.g., magnetospheric interactions). Once the location and distribution of UV-SAM's has been determined, further constraints on their composition can be made by analyzing the spectrographic data set. To accomplish these goals, various data sets will be used, including Voyager 2 UV and visible images of Triton's surface, IUE and HST spectra of Triton, and a geologic map of the surface based on Voyager 2 and spectrophotometric data. The results of this research will be published in the planetary science literature.

Stellar Occultation Probe of Triton's Atmosphere

NASA Technical Reports Server (NTRS)

Elliot, James L.

1998-01-01

The goals of this research were (i) to better characterize Triton's atmospheric structure by probing a region not well investigated by Voyager and (ii) to begin acquiring baseline data for an investigation of the time evolution of the atmosphere which will set limits on the thermal conductivity of the surface and the total mass of N2 in the atmosphere. Our approach was to use observations (with the Kuiper Airborne Observatory) of a stellar occultation by Triton that was predicted to occur on 1993 July 10. As described in the attached reprint, we achieved these objectives through observation of this occultation and a subsequent one with the KAO in 1995. We found new results about Triton's atmospheric structure from the analysis of the two occultations observed with the KAO and ground-based data. These stellar occultation observations made both in the visible and infrared, have good spatial coverage of Triton including the first Triton central-flash observations, and are the first data to probe the 20-100 km altitude level on Triton. The small-planet light curve model of Elliot and Young (AJ 103, 991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude indicating that Triton's atmosphere is spherically symmetric at approximately 50 km altitude to within the error of the measurements. However, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (approximately 20 km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 +/- 1 K and the atmospheric pressure at 1400 km radius (approximately 50 km altitude) is 1.4 +/- 0.1 microbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (Strobel et al, Icarus 120, 266-289). The atmospheric

New astrometric observations of Triton in 2007-2009

NASA Astrophysics Data System (ADS)

Qiao, R. C.; Zhang, H. Y.; Dourneau, G.; Yu, Y.; Yan, D.; Shen, K. X.; Cheng, X.; Xi, X. J.; Hu, X. Y.; Wang, S. H.

2014-06-01

Astrometric positions of the Neptunian satellite Triton with a visual magnitude of 13.5 were obtained during three successive oppositions in 2007, 2008 and 2009. A total of 1095 new observed positions of Triton were collected during 46 nights of observations, involving eight missions and three telescopes. We compared our observations to the best ephemerides of Triton available now. This comparison has shown that our observations present a high level of accuracy as they provide standard deviations of residuals hardly higher than 50 mas and mean residuals lower than 30 mas, corresponding to about only 500 km in the position of the very distant satellite Triton. Moreover, we have compared most of the different planetary ephemerides of Neptune available now as well as two recent orbit models of Triton. These new comparisons have clearly shown the differences between all of these ephemerides which can be significant and that are presented in this work.

Foil Artists

ERIC Educational Resources Information Center

Szekely, George

2010-01-01

Foil can be shaped into almost anything--it is the all-purpose material for children's art. Foil is a unique drawing surface. It reflects, distorts and plays with light and imagery as young artists draw over it. Foil permits quick impressions of a model or object to be sketched. Foil allows artists to track their drawing moves, seeing the action…

Redesigning TRACER trial after TRITON.

PubMed

Serebruany, Victor L

2015-10-15

Designing of smart clinical trials is critical for regulatory approval and future drug utilization. Importantly, trial design should be reconsidered if the interim analyses suggest unexpected harm, or conflicting results were yielded from the other trials within the same therapeutic area. With regard to antiplatelet agents, the perfect example is redesigning of the ongoing PRoFESS trial by eliminating aspirin from clopidogrel arm after the earlier MATCH trial results became available. The goal was to aseess the unchanged TRACER trial design in light of the evidence yielded from the earlier completed TRITON trial. TRACER was designed as a triple versus dual antiplatelet trial in NSTEMI patients with no previous long-term outcome data supporting such aggressive strategy. TRITON data represented dual versus dual antiplatelet therapy, and became available before TRACER enrollment starts revealing prasugrel front-loaded early vascular benefit predominantly in STEMI patients with the growing over time bleeding and cancer risks. Moreover, large prasugrel NSTEMI TRITON cohort exhibited trend towards excess mortality in experimental arm warning against aggressive TRACER design. The long-term TRITON results in general, and especially in the NSTEMI patients challenge unchanged TRACER trial design. Applying dual, rather than triple antiplatelet therapy protocol modification should be considered in TRACER to minimize bleeding, cancer, and non-cardiovascular death risks. Copyright © 2015. Published by Elsevier Ireland Ltd.

TRITON HYPERLIPEMIA IN DOGS

PubMed Central

Scanu, Angelo; Oriente, Pasquale; Szajewski, Janusz M.; McCormack, Lawrence J.; Page, Irvine H.

1961-01-01

Fourteen dogs, fed a regular diet and given 250 mg/kg of triton (a non-ionic surface-active agent) intravenously every 4th day, exhibited a progressively severe hyperlipemia. Serum triglycerides were the first to increase. Cholesterol, mostly in the free form, and phospholipids showed elevation only at a later stage and increased at almost identical rates. The plasma-free fatty acid concentration was from 2 to 3 times above normal. With establishment of sustained hyperlipemia, there was reduction, followed by total disappearance, of the high density D 1.063 to 1.21 lipoprotein. Most of the cholesterol and phospholipids (70 to 75 per cent of the total) were found in the D 1.006 to 1.063 lipoprotein class, the remainder in the D < 1.006 class. Triglycerides were almost evenly distributed between these two classes. The concentration of the serum lipoprotein proteins was within normal limits. All of the animals died within from 4 to 5 months after receiving the first injection of triton. Autopsy findings consistently showed: (a) numerous lipidladen macrophages in the liver, spleen, and lymph nodes; (b) significant depletion of all fat stores; (c) presence of lipids, either free or engulfed in macrophages (foam cells), in the subintima of the coronary arteries, aorta, and pulmonary arteries, indicating an early stage of atherosclerosis. Concurrent daily administration of heparin (5 mg per kilogram of body weight) did not substantially change the course of the disease. Withdrawal of triton from animals that had been receiving the detergent for from 3 to 4 months, elicited a slow return to normal of the lipid pattern. In two dogs killed when normolipemia was reestablished, all tissues were normal with the minor exception of a few hepatic macrophages still laden with sudanophilic material. It is postulated that the primary action of the injected triton was on the lipid moieties of plasma lipoproteins with formation of complexes, which, as foreign bodies, were

A New Model for the Seasonal Evolution of Triton

NASA Astrophysics Data System (ADS)

Forget, F.; Decamp, N.; Berthier, J.; Le Guyader, C.

2000-10-01

The seasonal evolution of Triton's surface and atmosphere remains poorly understood. No model [1] has been able to fully reproduce the main characterictics of the Voyager 2 observations in 1989 in combination with the "Global warming" recently inferred from stellar occultations [2]. Within this context, we have developped a new thermal model to study the seasonal nitrogen cycle on Triton. The model is the surface part of a Triton atmosphere General circulation model developped at LMD [3]. The nitrogen cycle was found to be very sensitive to Triton complex seasonal variations of the subsolar point latitude, especially during the current decade (south summer solstice). Since only pre-Voyager formulations were available for such a study, this has motivated some new calculations of Triton's motion based on more recent rotationnal elements combined with a relatively complete dynamic solution [4] adapted to Triton. A new analytic formulation suitable for climate modelling has been derived. On this basis, we wish to suggest a new, realistic scenario to explain Triton's apparence and evolution based on solar-induced variation of the frost albedo. Such variations have been observed in Mars CO2 ice seasonal polar caps [5]. Although they seem to result from complex microphysical behavior, they are likely to occur on Triton since both Triton and Mars polar caps are composed of weakly absorbing ice (N2 or CO2) in vapor pressure equilibrium with the main constituant of the atmosphere. [1] e.g. Hansen and Paige, Icarus 99, 273-288 (1992); Brown and Kirk, J. Geophys. Res. 99, 1965-1981 (1994); Spencer and Moore, Icarus 99, 261-272 (1992). [2] Elliot et al., Nature 393, 765-767 (1998). [3] Forget, Descamp and Hourdin, in ``Pluto and Triton, comparisons and evolution over time", Lowell Observatory's fourth annual workshop, Flagstaff, Arizona. (1999) [4] Le Guyader, Astron. Astrophys. 272, 687-694 (1993). [5] Kieffer et al., J. Geophys. Res. 105, 9653-9700 (2000).

Triton promotes domain formation in lipid raft mixtures.

PubMed

Heerklotz, H

2002-11-01

Biological membranes are supposed to contain functional domains (lipid rafts) made up in particular of sphingomyelin and cholesterol, glycolipids, and certain proteins. It is often assumed that the application of the detergent Triton at 4 degrees C allows the isolation of these rafts as a detergent-resistant membrane fraction. The current study aims to clarify whether and how Triton changes the domain properties. To this end, temperature-dependent transitions in vesicles of an equimolar mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, egg sphingomyelin, and cholesterol were monitored at different Triton concentrations by differential scanning calorimetry and pressure perturbation calorimetry. Transitions initiated by the addition of Triton to the lipid mixture were studied by isothermal titration calorimetry, and the structure was investigated by (31)P-NMR. The results are discussed in terms of liquid-disordered (ld) and -ordered (lo) bilayer and micellar (mic) phases, and the typical sequence encountered with increasing Triton content or decreasing temperature is ld, ld + lo, ld + lo + mic, and lo + mic. That means that addition of Triton may create ordered domains in a homogeneous fluid membrane, which are, in turn, Triton resistant upon subsequent membrane solubilization. Hence, detergent-resistant membranes should not be assumed to resemble biological rafts in size, structure, composition, or even existence. Functional rafts may not be steady phenomena; they might form, grow, cluster or break up, shrink, and vanish according to functional requirements, regulated by rather subtle changes in the activity of membrane disordering or ordering compounds.

Triton promotes domain formation in lipid raft mixtures.

PubMed Central

Heerklotz, H

2002-01-01

Biological membranes are supposed to contain functional domains (lipid rafts) made up in particular of sphingomyelin and cholesterol, glycolipids, and certain proteins. It is often assumed that the application of the detergent Triton at 4 degrees C allows the isolation of these rafts as a detergent-resistant membrane fraction. The current study aims to clarify whether and how Triton changes the domain properties. To this end, temperature-dependent transitions in vesicles of an equimolar mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, egg sphingomyelin, and cholesterol were monitored at different Triton concentrations by differential scanning calorimetry and pressure perturbation calorimetry. Transitions initiated by the addition of Triton to the lipid mixture were studied by isothermal titration calorimetry, and the structure was investigated by (31)P-NMR. The results are discussed in terms of liquid-disordered (ld) and -ordered (lo) bilayer and micellar (mic) phases, and the typical sequence encountered with increasing Triton content or decreasing temperature is ld, ld + lo, ld + lo + mic, and lo + mic. That means that addition of Triton may create ordered domains in a homogeneous fluid membrane, which are, in turn, Triton resistant upon subsequent membrane solubilization. Hence, detergent-resistant membranes should not be assumed to resemble biological rafts in size, structure, composition, or even existence. Functional rafts may not be steady phenomena; they might form, grow, cluster or break up, shrink, and vanish according to functional requirements, regulated by rather subtle changes in the activity of membrane disordering or ordering compounds. PMID:12414701

Historical photometric evidence for volatile migration on Triton

NASA Technical Reports Server (NTRS)

Buratti, Bonnie J.; Goguen, Jay D.; Gibson, James; Mosher, Joel

1994-01-01

Analysis of CCD images of Triton obtained with the 1.5-m telescope on Palomar Mountain shows that in the time period surrounding the Voyager 2 encounter with the satellite (1985-1990), no changes in the satellite's visual albedo or color occurred. The published observations of Triton in the 0.35- to 0.60-micrometer spectral region obtained between 1950 and 1990 were reanalyzed to detect historical variability in both its albedo and visual color. Analysis of the photometry indicates that there is little, if any, change in Triton's visual geometric albedo. This result is consistent with the albedo pattern observed by Voyager and the change in sub-Earth latitude. Two distinct types of color changes are evident: a significant secular increase in the blue region of the visual spectrum since at least the 1950s, and the reported dramatic reddening of Triton's spectrum in the late 1970s. The latter change can be explained only by a short-lived geological phenomenon. Triton's changing pole orientation with respect to a terrestrial observer cannot explain the secular color changes. These changes imply volatile transport on a global scale on Triton's surface during the past 4 decades. We present two models which show that either removal of a red volatile from Triton's polar cap or deposition of a blue volatile in the equatorial regions can explain the secular color changes. A third possibility is that the changes are the result of the alpha-beta phase transition of nitrogen and subsequent fracturing of the polar cap region (N. S. Duxbury and R. H. Brown (1993).

Sodar - Vaisala Triton Wind Profiler, AON8 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON2 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON9 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON1 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON3 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON8 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON5 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON5 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON7 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON2 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON8 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON1 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON6 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON7 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON4 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON9 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON4 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON2 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON4 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON9 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON7 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON6 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON5 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON6 - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON3 - Processed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON1 - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Triton's Summer Sky of Methane and Carbon Monoxide

NASA Astrophysics Data System (ADS)

2010-04-01

According to the first ever infrared analysis of the atmosphere of Neptune's moon Triton, summer is in full swing in its southern hemisphere. The European observing team used ESO's Very Large Telescope and discovered carbon monoxide and made the first ground-based detection of methane in Triton's thin atmosphere. These observations revealed that the thin atmosphere varies seasonally, thickening when warmed. "We have found real evidence that the Sun still makes its presence felt on Triton, even from so far away. This icy moon actually has seasons just as we do on Earth, but they change far more slowly," says Emmanuel Lellouch, the lead author of the paper reporting these results in Astronomy & Astrophysics. On Triton, where the average surface temperature is about minus 235 degrees Celsius, it is currently summer in the southern hemisphere and winter in the northern. As Triton's southern hemisphere warms up, a thin layer of frozen nitrogen, methane, and carbon monoxide on Triton's surface sublimates into gas, thickening the icy atmosphere as the season progresses during Neptune's 165-year orbit around the Sun. A season on Triton lasts a little over 40 years, and Triton passed the southern summer solstice in 2000. Based on the amount of gas measured, Lellouch and his colleagues estimate that Triton's atmospheric pressure may have risen by a factor of four compared to the measurements made by Voyager 2 in 1989, when it was still spring on the giant moon. The atmospheric pressure on Triton is now between 40 and 65 microbars - 20 000 times less than on Earth. Carbon monoxide was known to be present as ice on the surface, but Lellouch and his team discovered that Triton's upper surface layer is enriched with carbon monoxide ice by about a factor of ten compared to the deeper layers, and that it is this upper "film" that feeds the atmosphere. While the majority of Triton's atmosphere is nitrogen (much like on Earth), the methane in the atmosphere, first detected by

Foil changing apparatus

DOEpatents

Crist, Charles E.; Ives, Harry C.; Leifeste, Gordon T.; Miller, Robert B.

1988-01-01

A self-contained hermetically sealed foil changer for advancing a portion of foil web into a position normal to the path of a high energy particle beam. The path of the beam is defined generally by an aperture plate and cooperating axially movable barrel such that the barrel can be advanced toward the plate thereby positioning a portion of the foil across the beam path and sealing the foil between the barrel and the plate to form a membrane across said beam path. A spooling apparatus contained in the foil changer permits selectively advancing a fresh supply of foil across the beam path without breaking the foil changer seal.

Photometric diversity of terrains on Triton

NASA Technical Reports Server (NTRS)

Hillier, J.; Veverka, J.; Helfenstein, P.; Lee, P.

1994-01-01

Voyager disk-resolved images of Triton in the violet (0.41 micrometers) and green (0.56 micrometer wavelengths have been analyzed to derive the photometric characteristics of terrains on Triton. Similar conclusions are found using two distinct but related definitions of photometric units, one based on color ratio and albedo properties (A. S. McEwen, 1990), the other on albedo and brightness ratios at different phase angles (P. Lee et al., 1992). A significant diversity of photometric behavior, much broader than that discovered so far on any other icy satellite, occurs among Triton's terrains. Remarkably, differences in photometric behavior do not correlate well with geologic terrain boundaries defined on the basis of surface morphology. This suggests that in most cases photometric properties on Triton are controlled by thin deposits superposed on underlying geologic units. Single scattering albedos are 0.98 or higher and asymmetry factors range from -0.35 to -0.45 for most units. The most distinct scattering behavior is exhibited by the reddish northern units already identified as the Anomalously Scattering Region (ASR), which scatters light almost isotropically with g = -0.04. In part due to the effects of Triton's clouds and haze, it is difficult to constrain the value of bar-theta, Hapke's macroscopic roughness parameter, precisely for Triton or to map differences in bar-theta among the different photometric terrains. However, our study shows that Triton must be relatively smooth, with bar-theta less than 15-20 degs and suggests that a value of 14 degs is appropriate. The differences in photometric characteristics lead to significantly different phase angle behavior for the various terrains. For example, a terrain (e.g., the ASR) that appears dark relative to another at low phase angles will reverse its contrast (become relatively brighter) at larger phase angles. The photometric parameters have been used to calculate hemispherical albedos for the units and to

Triton's surface-atmosphere energy balance

USGS Publications Warehouse

Stansberry, J.A.; Yelle, R.V.; Lunine, J.I.; McEwen, A.S.

1992-01-01

We explore the energetics of Triton's surface-atmosphere system using a model that includes the turbulent transfer of sensible heat as well as insolation, reradiation, and latent heat transport. The model relies on a 1?? by 1?? resolution hemispheric bolometric albedo map of Triton for determining the atmospheric temperature, the N2 frost emissivity, and the temperatures of unfrosted portions of the surface consistent with a frost temperature of ???38 K. For a physically plausible range of heat transfer coefficients, we find that the atmospheric temperature roughly 1 km above the surface is approximately 1 to 3 K hotter than the surface. Atmospheric temperatures of 48 K suggested by early analysis of radio occultation data cannot be obtained for plausible values of the heat transfer coefficients. Our calculations indicate that Triton's N2 frosts must have an emissivity well below unity in order to have a temperature of ???38 K, consistent with previous results. We also find that convection over small hot spots does not significantly cool them off, so they may be able to act as continous sources of buoyancy for convective plumes, but have not explored whether the convection is vigorous enough to entrain particulate matter thereby forming a dust devil. Our elevated atmospheric temperatures make geyser driven plumes with initial upward velocities ???10 m s-1 stagnate in the lower atmosphere. These "wimpy" plumes provide a possible explanation for Triton's "wind streaks.". ?? 1992.

Triton Blushes: A Clue to Global Warming?

NASA Technical Reports Server (NTRS)

Buratti, B. J.; Hicks, M. D.; Newburn, R. L., Jr.

1998-01-01

The large Neptunian satellite Triton is a geologically active body that apparently undergoes complex seasonal changes in its 165 year journey around the sun. Because it is the vehicle for the seasonal transport of volatiles, Triton's atmosphere is expected to undergo large changes in temperature and pressure on a time scale of decades.

The Revised Pole Model and New Observations of Triton

NASA Astrophysics Data System (ADS)

Zhang, H.-Y.; Shen, K.-X.; Qiao, R.-Ch; Dourneau, G.; Yu, Y.

2015-10-01

We used 3108 Earth-based astrometric observations from the Natural Satellite Data Center (NSDC) over more than 30 years time span from 1975 to 2006 for determining the epoch state vectors of the Neptunes largest satellite Triton. In integrating the perturbation equation, the barycentric frame of Neptune-Triton system is adopted, and in considering the oblateness perturbation due to Neptune, a revised pole model describing the precession of the Neptune's pole is used in our calculation. Moreover, a total of 1095 new observed positions of Triton were collected during 46 nights of observations in 2007, 2008 and 2009. We compared our observations to two ephemerides of Triton and most of the available planetary ephemerides of Neptune.

Voyager IRIS Measurements of Triton's Thermal Emission: Impllications for Pluto?

NASA Astrophysics Data System (ADS)

Stansberry, John A.; Spencer, John; Linscott, Ivan

2015-11-01

The New Horizons Pluto encounter data set includes unique observations obtained using the Radio Science experiment to measure the night-side thermal emission at centimeter wavelengths, well beyond the emission peak (in the 70 to 100 micron range). 26 years ago the Voyager 2 Infrared Interferometer Spectrometer (IRIS) obtained spectra in the 30 - 50 micron wavelength range to try and detect thermal emission from Pluto's sibling, Triton. Conrath etal. (1989) analyzed 16 of the IRIS spectra of Triton's dayside and derived a weak limit of 36 K - 41 K. We have analysed those, and an additional 75 spectra, to refine the limits on the temperature of Triton's surface, and to explore diurnal differences in the thermal emission. Triton results from other Voyager instruments provide important constraints on our interpretation of the IRIS data, as do Spitzer measurements of Pluto's thermal emission.For unit-emissivity, average temperature is 34 K, inconsistent with the pressure of Triton's atmosphere (13 - 19 microbar), the presence of beta-phase nitrogen ice on the surface, and the likely presence ofwarm regions on the surface. The atmospheric pressure requires nitrogen ice temperatures of 37.4 K - 38.1 K, which in turn requires emissivity of 0.31--0.53. Such a low emissivity in this spectral region might be expected if the surface is dominated by nitrogen or methane ice. Averages of data subsets show evidence for brightness temperature variations across Triton's surface. Surprisingly, the data seem to indicate that Triton's nightside equatorial region was warmer than on the dayside.These Voyager results for Triton provide a useful context for interpreting New Horizons and ALMA observations of emission from Pluto in the sub-millimeter and centimeter region. JWST will be capable of detecting Triton's and Pluto's 10 - 28 micron thermal emission, although scattered light from Neptune may be an issue for the Triton. Combined with new capabilities of ALMA to measure the sub

Color and chemistry on Triton

NASA Technical Reports Server (NTRS)

Thompson, W. Reid; Sagan, Carl

1990-01-01

The surface of Triton is very bright but shows subtle yellow to peach hues which probably arise from the production of colored organic compounds from CH4 + N2 and other simple species. In order to investigate possible relationships between chemical processes and the observed surface distribution of chromophores, the surface units are classified according to color/albedo properties, the rates of production of organic chromophores by the action of ultraviolet light and high-energy charged particles is estimated, and rates, spectral properties, and expected seasonal redistribution processes are compared to suggest possible origins of the colors seen on Triton's surface.

Triton stellar occultation candidates - 1992-1994

NASA Technical Reports Server (NTRS)

Mcdonald, S. W.; Elliot, J. T.

1992-01-01

A search for Triton stellar occultation candidates for the period 1992-1994 has been completed with CCD strip-scanning observations. The search reached an R magnitude of about 17.4 and found 129 candidates within 1.5 arcsec of Triton's ephemeris during this period. Of these events, around 30 occultations are expected to be visible from the earth, indicating that a number of Triton occultation events should be visible from major observatories. Even the faintest of the present candidate events could produce useful occultation data if observed with a large enough telescope. The present astrometric accuracy is inadequate to identify which of these appulse events will produce occultations on the earth; further astrometry is needed to refine the predictions for positive occultation identification. To aid in selecting candidates for additional astrometric and photometric studies, finder charts and earth-based visibility charts for each event are included.

Building a Geologic Map of Neptune's Moon Triton

NASA Astrophysics Data System (ADS)

Martin, E. S.; Patthoff, D. A.; Bland, M. T.; Watters, T. R.; Collins, G. C.; Becker, T.

2018-06-01

Triton serves as a bridge between KBOs and icy satellites, and characterization of its terrains is important for advancing comparative planetological studies. We aim to create a geologic map of the Neptune-facing side of Triton at a scale of 1:5M.

Thrust augmentation in tandem flapping foils by foil-wake interaction

NASA Astrophysics Data System (ADS)

Anderson, Erik; Lauder, George

2006-11-01

Propulsion by pitching and heaving airfoils and hydrofoils has been a focus of much research in the field of biologically inspired propulsion. Organisms that use this sort of propulsion are self-propelled, so it is difficult to use standard experimental metrics such as thrust and drag to characterize performance. We have constructed a flapping foil robot mounted in a flume on air-bearings that allows for the determination of self-propelled speed as a metric of performance. We have used a pair of these robots to examine the impact of an upstream flapping foil on a downstream flapping foil as might apply to tandem fins of a swimming organism or in-line swimming of schooling organisms. Self-propelled speed and a force transducer confirmed significant thrust augmentation for particular foil-to-foil spacings, phase differences, and flapping frequencies. Flow visualization shows the mechanism to be related to the effective angle of attack of the downstream foil due to the structure of the wake of the upstream foil. This confirms recent computational work and the hypotheses by early investigators of fish fluid dynamics.

The Surface Compositions of Triton, Pluto, and Charon

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.; Roush, Ted L.; Owen, Tobias C.; Quirico, Eric; DeBergh, Catherine

1995-01-01

Neptune's satellite Triton, and the planet-satellite binary Pluto and Charon, are the most distant planetary bodies on which ices have been directly detected. Triton and Pluto have very similar dimensions and mean densities, suggesting a similar or common origin. Through earth-based spectroscopic observations in the near-infrared, solid N2, CH4, and CO have been found on both bodies, with the additional molecule C02 on Triton. N2 dominates both surfaces, although the coverage is not spatially uniform. On Triton, the CH4 and CO are mostly or entirely frozen in the N2 matrix, while CO2 may be spatially segregated. On Pluto, some CH4 and the CO are frozen in the N2 matrix, but there is evidence for additional CH4 in a pure state, perhaps lying as a lag deposit on a subsurface layer of N2. Despite their compositional and dimensional similarities, Pluto and Triton are quite different from one another in detail. Additional hydrocarbons and other volatile ices have been sought spectroscopically but not yet have been detected. The only molecule identified on Pluto's satellite Charon is solid H2O, but the spectroscopic data are of low precision and admit the presence of other ices such as CH4.

The Structure of Triton's Lower Atmosphere

NASA Astrophysics Data System (ADS)

Bosh, Amanda

1995-07-01

With the occultation of Tr148 (McDonald and Elliot, submitted) in August 1995, we have the opportunity to distinguish between two competing models for Triton's lower atmosphere (Tyler et al. 1989; Strobel and Summers 1994). Additionally, we will be acquiring data on an atmosphere that has been predicted to be changing quite rapidly (Hansen and Paige 1992; Spencer and Moore 1992). High quality occultation data sets are crucial for testing these theories and establishing the changing state of Triton's atmosphere.

Observation of an Opposition Surge on Triton

NASA Astrophysics Data System (ADS)

Herbert, B. D.; Buratti, B. J.; Schmidt, B.; Bauer, J. M.; Hicks, M. D.

2004-11-01

Ground-based observations of Neptune's moon Triton taken during the summers of 2000, 2003, and 2004 show a rotational light curve with a large amplitude. This is in stark contrast to data from the 1989 Voyager II flyby, which implies significant changes have occurred on Triton's surface since that time. The light curve has two notable regions, one that is significantly brighter than was observed in 1989 and one that is significantly darker. Data were also taken at a broad range of solar phase angles, allowing for a comprehensive study of the effects of phase on Triton's brightness. Analysis of the phase curve yields a solar phase coefficient close to zero for phases greater than 0.08 degrees, a number in close agreement with past studies that focused on higher phase angles. We also report a previously unrecognized opposition surge. Preliminary analysis suggests that the surge has different characteristics in the dark and bright regions currently visible on Triton, implying a non-homogenous regolith. Funding for this project was provided in part by the New York Space Grant Consortium and the NASA Undergraduate Student Research Program.

Triton's streaks as windblown dust

NASA Technical Reports Server (NTRS)

Sagan, Carl; Chyba, Christopher

1990-01-01

Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

A massive early atmosphere on Triton

NASA Technical Reports Server (NTRS)

Lunine, Jonathan I.; Nolan, Michael C.

1992-01-01

The idea of an early greenhouse atmosphere for Triton is presented and the conditions under which it may have been sustained are quantified. The volatile content of primordial Triton is modeled, and tidal heating rates are assessed to set bounds on the available energy. The atmospheric model formalism is presented, and it is shown how a massive atmosphere could have been raised by modest tidal heating fluxes. The implications of the model atmospheres for the atmospheric escape rates, the chemical evolution, and the cratering record are addressed.

Energy sources for triton's geyser-like plumes

USGS Publications Warehouse

Brown, R.H.; Kirk, R.L.; Johnson, T.V.; Soderblom, L.A.

1990-01-01

Four geyser-like plumes were discovered near Triton's south pole in areas now in permanent sunlight. Because Triton's southern hemisphere is nearing a maximum summer solstice, insolation as a driver or a trigger for Triton's geyser-like plumes is an attractive hypothesis. Trapping of solar radiation in a translucent, low-conductivity surface layer (in a solid-state greenhouse), which is subsequently released in the form of latent heat of sublimation, could provide the required energy. Both the classical solid-state greenhouse consisting of exponentially absorbed insolation in a gray, translucent layer of solid nitrogen, and the "super" greenhouse consisting of a relatively transparent solid-nitrogen layer over an opaque, absorbing layer are plausible candidates. Geothermal heat may also play a part if assisted by the added energy input of seasonal cycles of insolation.

Pluto and Triton: Interactions Between Volatiles and Dynamics

NASA Technical Reports Server (NTRS)

Rubincam, D. P.

2001-01-01

Volatiles moving across the surfaces of Pluto and Triton can give rise to interesting dynamical consequences. Conversely, measurement of dynamical states can help constrain the movement of volatiles and interior structure of both bodies. Polar wander may theoretically occur on both Triton and Pluto. Triton's obliquity is low, so that the equatorial regions receive more insolation than the poles. Hence there is a tendency for nitrogen ice to sublime at the equator and condense at the poles, creating polar caps. If the nitrogen supply is large enough, then these caps could move in approximately 10(exp 5) years the global equivalent of 200 m of ice to the poles. At this point the equatorial moment of inertia becomes larger than the moment of inertia measured about the rotation axis, so that Triton overbalances and becomes dynamically unstable. The satellite then undergoes polar wander, restoring stability when the new equator contains the excess matter. Hence the pole may be continually wandering. Neptune raises a permanent tidal bulge on Triton, so that the satellite's surface is elongated like a football, with the long axis pointing at Neptune. This is expected to be the axis about which the pole wanders. Volatile migration would resurface the satellite to some depth and wandering would disturb leading side/trailing side crater statistics. Additional information is contained in the original extended abstract.

Pluto and Triton: Interactions Between Volatiles and Dynamics

NASA Astrophysics Data System (ADS)

Rubincam, D. P.

2001-01-01

Volatiles moving across the surfaces of Pluto and Triton can give rise to interesting dynamical consequences. Conversely, measurement of dynamical states can help constrain the movement of volatiles and interior structure of both bodies. Polar wander may theoretically occur on both Triton and Pluto. Triton's obliquity is low, so that the equatorial regions receive more insolation than the poles. Hence there is a tendency for nitrogen ice to sublime at the equator and condense at the poles, creating polar caps. If the nitrogen supply is large enough, then these caps could move in approximately 105 years the global equivalent of 200 m of ice to the poles. At this point the equatorial moment of inertia becomes larger than the moment of inertia measured about the rotation axis, so that Triton overbalances and becomes dynamically unstable. The satellite then undergoes polar wander, restoring stability when the new equator contains the excess matter. Hence the pole may be continually wandering. Neptune raises a permanent tidal bulge on Triton, so that the satellite's surface is elongated like a football, with the long axis pointing at Neptune. This is expected to be the axis about which the pole wanders. Volatile migration would resurface the satellite to some depth and wandering would disturb leading side/trailing side crater statistics. Additional information is contained in the original extended abstract.

Neptune and Triton: A Study in Future Exploration

NASA Astrophysics Data System (ADS)

Day, M. D.; Malaska, M. J.; Hosseini, S.; Mcgranaghan, R.; Fernandes, P. A.; Fougere, N.; Clegg, R. N.; Scully, J.; Alibay, F.; Ries, P.; Craig, P. L.; Hutchins, M. L.; Leonard, J.; Uckert, K.; Patthoff, A.; Girazian, Z.

2013-12-01

Neptune provides a unique natural laboratory for studying the dynamics of ice giants. Last visited by Voyager 2 in 1989, Neptune and its moon Triton hold important clues to the evolution of the solar system. The Voyager 2 flyby revealed Neptune to be a dynamic world with large storms, unparalleled wind speeds, and an unusual magnetic field. Triton, Neptune's largest satellite, is believed to be a captured Kuiper Belt Object with a thin atmosphere and possible sub-surface ocean. Further study of the farthest planet in our solar system could offer new insights into the dynamics of ice-giant exoplanets, and help us understand their complex atmospheres. The diverse science questions associated with Neptune and Triton motivate the complex and exciting mission proposed in this study. The proposed mission follows the guidelines of the 2013-2022 Planetary Science Decadal Survey, and optimizes the number of high priority science goals achieved, while still maintaining low mission costs. High priority science goals include understanding the structure, composition, and dynamics of Neptune's atmosphere and magnetosphere, as well as analyzing the surface of Triton. With a budget of $1.5 billion, the mission hosts an atmospheric probe and suite of instruments equipped with technologies significantly more advanced than those carried by Voyager 2. Additionally, the mission offers improved spatial coverage and higher resolution measurements than any previously achieved at Neptune. The proposed spacecraft would complete an orbital tour of Neptune and execute several close flybys of Triton. Further study of Neptune and Triton will provide exciting insights into what lies on the edge of our solar system and beyond. This study was prepared in conjunction with Jet Propulsion Laboratory's 2013 Planetary Science Summer School.

Triton - Stratospheric molecules and organic sediments

NASA Technical Reports Server (NTRS)

Thompson, W. Reid; Singh, Sushil K.; Khare, B. N.; Sagan, Carl

1989-01-01

Continuous-flow plasma discharge techniques show production rates of hydrocarbons and nitriles in N2 + CH4 atmospheres appropriate to the stratosphere of Titan, and indicate that a simple eddy diffusion model together with the observed electron flux quantitatively matches the Voyager IRIS observations for all the hydrocarbons, except for the simplest ones. Charged particle chemistry is very important in Triton's stratosphere. In the more CH4-rich case of Titan, many hydrocarbons and nitriles are produced in high yield. If N2 is present, the CH4 fraction is low, but hydrocarbons and nitriles are produced in fair yield, abundances of HCN and C2H2 in Triton's stratosphere exceed 10 to the 19th molecules/sq cm per sec, and NCCN, C3H4, and other species are predicted to be present. These molecules may be detected by IRIS if the stratosphere is as warm as expected. Both organic haze and condensed gases will provide a substantial UV and visible opacity in Triton's atmosphere.

Triton-polyacrylamide gel electrophoresis and leucine aminopeptidase activity staining detect Triton-slowed bands including high-molecular-mass aminopeptidase N (CD13) isoform in cholestatic patient sera.

PubMed

Kawai, Makoto; Hara, Yukichi

2006-02-01

Western blotting of aminopeptidase N (APN) detects a high-molecular-mass isoform (260 kDa) [M. Kawai, Y. Otake, Y. Hara High-molecular-mass isoform of aminopeptidase N/CD13 in serum from cholestatic patients. Clin Chim Acta 330 (2003) 141-149] in cholestatic patient serum but is time-consuming. Human sera were electrophoresed on polyacrylamide gel containing Triton-X100 (Triton-PAGE) and stained with leucine-B-naphthylamide (LAP-staining). The stained bands were eluted from the gel, treated with N- and O-glycosidase if necessary, and analyzed by Western blotting [M. Kawai, Y. Otake, Y. Hara High-molecular-mass isoform of aminopeptidase N/CD13 in serum from cholestatic patients. Clin Chim Acta 330 (2003) 141-149]. Triton-PAGE and LAP-staining clearly detected fast bands in all the sera examined. Almost parallel with leucine aminopeptidase activity, slow bands were strongly stained in all 11 cholestatic patients but clearly stained in 3 out of 14 patients with hepatobiliary diseases other than cholestasis. PAGE with various concentrations of Triton showed that Triton slows down slow bands but not fast bands. Western blotting showed that Triton-PAGE-slow bands of cholestasis contained 140 and 260-kDa APN and that fast bands were slightly smaller than monomer-size slow bands after glycosidase treatment. Less time-consuming than Western blotting, Triton-PAGE and LAP-staining detect novel APN bands slowed by Triton and partly composed of the high-molecular-mass isoform in cholestasis. The slow bands seem to be homodimers of APN with transmembrane anchors. The polypeptide of the fast band seems to be processed differently from that of the slow band.

Triton College, 1980-1982.

ERIC Educational Resources Information Center

Triton Coll., River Grove, IL.

Focusing on the period from 1980 to 1982, this public information booklet reviews the accomplishments and innovative programs of Triton College. After an introduction by the college president summarizing these achievements, subsequent sections focus on: (1) training partnerships with business and industry, including cooperative agreements with the…

Triton Hopper: Exploring Neptune's Captured Kuiper Belt Object

NASA Technical Reports Server (NTRS)

Oleson, Steve; Landis, Geoffrey

2018-01-01

Neptune's moon Triton is a fascinating object, a dynamic moon with an atmosphere, and geysers. Triton is unique in the outer solar system in that it is most likely a captured Kuiper belt object (KBO), a leftover building block of the solar system. When Voyager flew by it was the coldest body yet found in our solar system (33 degrees Kelvin) and had volcanic activity, geysers, and a thin atmosphere. It is covered in ices made from nitrogen, water, and carbon-dioxide, and shows surface deposits of tholins, organic compounds that may be precursor chemicals to the origin of life. Exploring Triton will be a challenge well beyond anything done in previous missions; but the unique environment of Triton also allows some new possibilities for mobility. We developed a conceptual design of a Triton Hopping probe that both analyzes the surface and collects it for use to propel its hops. The Hopper would land near the South Pole in 2040 where geysers have been detected. Depending the details of propulsion chosen the Hopper should be able to jump over 300 kilometers in 60 hops or less, exploring the surface and thin atmosphere on its way. This craft will autonomously carry out detailed scientific investigations on the surface, below the surface (drilling) and in the upper atmosphere to provide unprecedented knowledge of a KBO-turned moon and expanding NASA's existing capabilities in deep space planetary exploration to include Hoppers using different ices for propellant. Triton is roughly 2700 kilometers in diameter with a surface of mostly frozen nitrogen, mostly water ice crust and core of metal and rock. Its gravity is half that of Earth's Moon and its atmosphere is 170,000th of Earth's or 0.3 of Mars.The mission concept studied investigated the full surface and atmospheric phenomenon: chemical composition of surface and near subsurface materials, the thin atmosphere, volcanic and geyser activity. Measurements of all these aspects of Triton's unique environment can only be

Temperature and thermal emissivity of the surface of Neptune's satellite Triton

NASA Technical Reports Server (NTRS)

Nelson, Robert M.; Smythe, William D.; Wallis, Brad D.; Horn, Linda J.; Lane, Arthur L.; Mayo, Marvin J.

1990-01-01

Analysis of the preliminary results from the Voyager mission to the Neptune system has provided the scientific community with several methods by which the temperature of Neptune's satellite Triton may be determined. If the 37.5 K surface temperature reported by several Voyager investigations is correct, then the photometry reported by the imaging experiment on Voyager requires that Triton's surface have a remarkably low emissivity. Such a low emissivity is not required in order to explain the photometry from the photopolarimeter experiment on Voyager. A low emissivity would be inconsistent with Triton having a rough surface at the about 100-micron scale as might be expected given the active renewal processes which appear to dominate Triton's surface.

Foil Face Seal Testing

NASA Technical Reports Server (NTRS)

Munson, John

2009-01-01

In the seal literature you can find many attempts by various researchers to adapt film riding seals to the gas turbine engine. None have been successful, potential distortion of the sealing faces is the primary reason. There is a film riding device that does accommodate distortion and is in service in aircraft applications, namely the foil bearing. More specifically a foil thrust bearing. These are not intended to be seals, and they do not accommodate large axial movement between shaft & static structure. By combining the 2 a unique type of face seal has been created. It functions like a normal face seal. The foil thrust bearing replaces the normal primary sealing surface. The compliance of the foil bearing allows the foils to track distortion of the mating seal ring. The foil seal has several perceived advantages over existing hydrodynamic designs, enumerated in the chart. Materials and design methodology needed for this application already exist. Also the load capacity requirements for the foil bearing are low since it only needs to support itself and overcome friction forces at the antirotation keys.

Cellular lysis of Streptococcus faecalis induced with triton X-100.

PubMed Central

Cornett, J B; Shockman, G D

1978-01-01

Lysis of exponential-phase cultures of Streptococcus faecalis ATCC 9790 was induced by exposure to both anionic (sodium dodecyl sulfate) and nonionic (Triton X-100) surfactants. Lysis in response to sodium dodecyl sulfate was effective only over a limited range of concentrations, whereas Triton X-100-induced lysis occurred over a broad range of surfactant concentrations. The data presented indicate that the bacteriolytic response of growing cells to Triton X-100: (i) was related to the ratio of surfactant to cells and not the surfactant concentration per se; (ii) required the expression of the cellular autolytic enzyme system; and (iii) was most likely due to an effect of the surfactant on components of the autolytic system that are associated with the cytoplasmic membrane. The possibility that Triton X-100 may induce cellular lysis by releasing a lipid inhibitor of the cellular autolytic enzyme is discussed. PMID:97265

Triton stellar occultation candidates: 1995-1999

NASA Technical Reports Server (NTRS)

Mcdonald, S. W.; Elliot, J. L.

1995-01-01

We have completed a search for candidates for stellar occultations by Triton over the years 1995-1999. CCd strip scan images provided star positions in the relevant sky area to a depth of about 17.5 R magnitude. Over this time period, we find that Triton passes within 1.0 arcsec of 75 stars. Appulses with geocentric minimum separations of less than 0.35 arcsec will result in stellar occultations, but further astrometry and photometry is necessary to refine individual predictions for identification of actual occultations. Finder charts are included to aid in further studies and prediction refinement. The two most promising potential occultations, Tr176 and Tr180, occur in 1997.

The first UV spectrum of Triton - IUE observations from 2600 to 3200 A

NASA Technical Reports Server (NTRS)

Stern, S. Alan; Skinner, T. E.; Brosch, N.; Van Santvoort, J.; Trafton, L. M.

1989-01-01

The results of the first observations of Triton's spectrum below 3300 A are reported. Triton's 2700 A geometric albedo is found to be 0.28 + or - 0.04. The albedo increases monotonically from 2600 to 3200 A, with a slope of 0.13 + or - 0.03 per 1000 A. This positive slope is qualitatively similar to, but shallower than, Triton's visible albedo slope and argues against a strong Rayleigh scattering signature. Triton's integrated flux is found to be 1.5 times Pluto's, indicating Triton to be either more reflective in the UV, or bigger, or both. The redness of Triton's visible and UV colors argues against an extremely bright surface and for a larger radius than Pluto's. A lower limit on the radius of 1240 + or - 90 km is derived. The spectrum observed by IUE is consistent with either an icy surface or a suspended aerosol layer which preferentially absorbs UV light.

Surface treatment using metal foil liner

NASA Technical Reports Server (NTRS)

Garvey, Ray

1989-01-01

A metal foil liner can be used to seal large area surfaces. Characteristics of the two-layer foil liner are discussed. Micrographs for foil-to-foil, foil-to-composite, visible seams, and hidden seams are examined.

Some constraints on a greenhouse atmosphere for Triton

NASA Technical Reports Server (NTRS)

Nolan, Michael C.; Lunine, Jonathan I.

1988-01-01

The possibility that a thick atmosphere exists around Neptune's satellite Triton is examined. The IR optical depth in the gray atmosphere approximation is computed for a range of possible surface compositions, albedos, and gravities. It is found that a self-sustaining optically-thick atmosphere is possible if molecular nitrogen and/or hydrogen are present. It is suggested that bimodal behavior of Triton's atmosphere is possible as seasonal effects and volatile distribution alter the distribution of thermal emission.

Large quasi-circular features beneath frost on Triton

NASA Technical Reports Server (NTRS)

Helfenstein, Paul; Veverka, Joseph; Mccarthy, Derek; Lee, Pascal; Hillier, John

1992-01-01

Specially processed Voyager 2 images of Neptune's largest moon, Triton, reveal three large quasi-circular features ranging in diameter from 280 to 935 km within Triton's equatorial region. The largest of these features contains a central irregularly shaped area of comparatively low albedo about 380 km in diameter, surrounded by crudely concentric annuli of higher albedo materials. None of the features exhibit significant topographic expression, and all appear to be primarily albedo markings. The features are located within a broad equatorial band of anomalously transparent frost that renders them nearly invisible at the large phase angles (alpha greater than 90 deg) at which Voyager obtained its highest resolution coverage of Triton. The features can be discerned at smaller phase angles (alpha = 66 deg) at which the frost only partially masks underlying albedo contrasts. The origin of the features is uncertain but may have involved regional cryovolcanic activity.

Surfactant-enhanced remediation of a trichloroethene-contaminated aquifer. 1. Transport of triton X-100

USGS Publications Warehouse

Smith, J.A.; Sahoo, D.; Mclellan, H.M.; Imbrigiotta, T.E.

1997-01-01

Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer at Picatinny Arsenal, NJ, has been studied through a series of laboratory and field experiments. In the laboratory, batch and column experiments were conducted to quantify the rate and amount of Triton X-100 sorption to the aquifer sediments. In the field, a 400 mg/L aqueous Triton X-100 solution was injected into the aquifer at a rate of 26.5 L/min for a 35-d period. The transport of Triton X-100 was monitored by sampling and analysis of groundwater at six locations surrounding the injection well. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to critical micelle concentration. Batch, soil column, and field experimental data were analyzed with zero-, one-, and two- dimensional (respectively) transient solute transport models with either equilibrium or rate-limited sorption. These analyses reveal that Triton X- 100 sorption to the aquifer solids is slow relative to advective and dispersive transport and that an equilibrium sorption model cannot simulate accurately the observed soil column and field data. Comparison of kinetic sorption parameters from batch, column, and field transport data indicate that both physical heterogeneities and Triton X-100 mass transfer between water and soil contribute to the kinetic transport effects.Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer was studied. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to

Triton - Detail of Dark and Light Material

NASA Image and Video Library

1996-09-26

NASA's Voyager 2 acquired this black and white image of Triton, Neptune's largest satellite, during the night of Aug. 24-25, 1989. Triton's limb cuts obliquely across the middle of the image. The field of view is about 1,000 km (600 miles) across. Three irregular dark areas, surrounded by brighter material, dominate the image. Low-lying material with intermediate albedo occupies the central area, and fresh craters occur along the right margin. Sub-parallel alignment of linear patches of dark material shown in the lower and left part of the image suggests that the patches are structurally controlled. http://photojournal.jpl.nasa.gov/catalog/PIA00056

Voyager radio science observations of neptune and triton.

PubMed

Tyler, G L; Sweetnam, D N; Anderson, J D; Borutzki, S E; Campbell, J K; Eshleman, V R; Gresh, D L; Gurrola, E M; Hinson, D P; Kawashima, N; Kursinski, E R; Levy, G S; Lindal, G F; Lyons, J R; Marouf, E A; Rosen, P A; Simpson, R A; Wood, G E

1989-12-15

The Voyager 2 encounter with the Neptune system included radio science investigations of the masses and densities of Neptune and Triton, the low-order gravitational harmonics of Neptune, the vertical structures of the atmospheres and ionospheres of Neptune and Triton, the composition of the atmosphere of Neptune, and characteristics of ring material. Demanding experimental requirements were met successfully, and study of the large store of collected data has begun. The initial search of the data revealed no detectable effects of ring material with optical depth tau [unknown] 0.01. Preliminary representative results include the following: 1.0243 x 10(26) and 2.141 x 10(22) kilograms for the masses of Neptune and Triton; 1640 and 2054 kilograms per cubic meter for their respective densities; 1355 +/- 7 kilometers, provisionally, for the radius of Triton; and J(2) = 3411 +/- 10(x 10(-6)) and J(4) = -26(+12)(-20)(x10(-6)) for Neptune's gravity field (J>(2) and J(4) are harmonic coefficients of the gravity field). The equatorial and polar radii of Neptune are 24,764 +/- 20 and 24,340 +/- 30 kllometers, respectively, at the 10(5)-pascal (1 bar) pressure level. Neptune's atmosphere was probed to a pressure level of about 5 x 10(5) pascals, and effects of a methane cloud region and probable ammonia absorption below the cloud are evident in the data. Results for the mixing ratios of helium and ammonia are still being investigated; the methane abundance below the clouds is at least 1 percent by volume. Derived temperature-pressure profiles to 1.2 x 10(5) pascals and 78 kelvins (K) show a lapse rate corresponding to "frozen" equilibrium of the para- and ortho-hydrogen states. Neptune's ionosphere exhibits an extended topside at a temperature of 950 +/- 160 K if H(+) is the dominant ion, and narrow ionization layers of the type previously seen at the other three giant planets. Triton has a dense ionosphere with a peak electron concentration of 46 x 10(9) per cubic meter at an

MQ-4C Triton Unmanned Aircraft System (MQ-4C Triton)

DTIC Science & Technology

2015-12-01

will respond to theater level operational or national strategic taskings. MQ-4C Triton December 2015 SAR March 23, 2016 15:26:01 UNCLASSIFIED 6...88% at a mission radius of 2,000 nm Level of Interoperability 1-5 BLOS and LOS from MOB/ FOB (Land Based) MCS BLOS and LOS from MOB/ FOB (Land...MCS UA Mission Radius >=3,000 nm >=3,000 nm >=2,000 nm TBD >=2,000 nm Level Of Interoperability 2 Capability LOS/BLOS multi-ISR payload reception to

Chemical investigation of Titan and Triton tholins

NASA Technical Reports Server (NTRS)

Mcdonald, Gene D.; Thompson, W. R.; Heinrich, Michael; Khare, Bishun N.; Sagan, Carl

1994-01-01

We report chromatographic and spectroscopic analyses of both Titan and Triton tholins, organic solids made from the plasma irradiation of 0.9:0.1 and 0.999:0.001 N2/CH4 gas mixtures, respectively. The lower CH4 mixing ratio leads to a nitrogen-richer tholin (N/C greater than 1), probably including nitrogen heterocyclic compounds. Unlike Titan tholin, bulk Triton tholin is poor in nitriles. From high-pressure liquid chromatography, ultraviolet and infrared spectroscopy, and molecular weight estimation by gel filtration chromatography, we conclude that (1) several H2O-soluble fractions, each with distinct UV and IR spectral signatures, are present, (2) these fractions are not identical in the two tholins, (3) the H2O-soluble fractions of Titan tholins do not contain significant amounts of nitriles, despite the major role of nitriles in bulk Titan tholin, and (4) the H2O-soluble fractions of both tholins are mainly molcules containing about 10 to 50 (C + N) atoms. We report yields of amino acids upon hydrolysis of Titan and Triton tholins. Titan tholin is largely insoluble in the putative hydrocarbon lakes or oceans on Titan, but can yield the H2O-soluble species investigated here upon contact with transient (e.g., impact-generated) liquid water.

Chromic acid anodizing of aluminum foil

NASA Technical Reports Server (NTRS)

Dursch, H.

1988-01-01

The success of the Space Station graphite/epoxy truss structure depends on its ability to endure long-term exposure to the LEO environment, primarily the effects of atomic oxygen and the temperture cycling resulting from the 94 minute orbit. This report describes the development and evaluation of chromic acid anodized (CAA) aluminum foil as protective coatings for these composite tubes. Included are: development of solar absorptance and thermal emittance properties required of Al foil and development of CAA parameters to achieve these optical properties; developing techniques to CAA 25 ft lengths of Al foil; developing bonding processes for wrapping the Al foil to graphite/epoxy tubes; and atomic oxygen testing of the CAA Al foil. Two specifications were developed and are included in the report: Chromic Acid Anodizing of Aluminum Foil Process Specification and Bonding of Anodized Aluminum Foil to Graphite/Epoxy Tubes. Results show that CAA Al foil provides and excellent protective and thermal control coating for the Space Station truss structure.

Triton's surface properties - A preliminary analysis from ground-based, Voyager photopolarimeter subsystem, and laboratory measurements

NASA Technical Reports Server (NTRS)

Buratti, B. J.; Lane, A. L.; Gibson, J.; Burrows, H.; Nelson, R. M.; Bliss, D.; Smythe, W.; Garkanian, V.; Wallis, B.

1991-01-01

The surface properties of Triton were investigated using data from the ground-based and Voyager photopolarimeter subsystem (PPS) observations of Triton's phase curve. The results indicate that Triton has a high single-scattering albedo (0.96 +/-0.01 at 0.75 micron) and an unusually compacted surface, possibly similar to that of Europa. Results also suggest that Triton's single-particle phase function and the macroscopically rough character of its surface are similar to those of most other icy satellites.

The Effects of Tidal Dissipation on the Thermal Evolution of Triton

NASA Astrophysics Data System (ADS)

Gaeman, J.; Hier-Majumder, S.; Roberts, J. H.

2009-12-01

This work explores the coupled structural, thermal, and orbital evolution of Neptune's icy satellite, Triton. Recent geyser activity, ridge formation, and volatile transport, observed on Triton's surface, indicate possible activity within Triton's interior [1,2]. Triton is hypothesized to have been captured from an initially heliocentric orbit. During the circularization of Triton's orbit following its capture by Neptune, intense tidal heating likely contributed to the formation of a subsurface ocean [3]. Although the time of Triton's capture is not exactly known, it is likely that the event took place earlier in the history of our solar system, when the probability of binary capture was higher [4, 5]. This work examines the thermal evolution of Triton by employing a coupled tidal and two-phase thermal evolution model, for both an early and late capture scenario. Thermal evolution of a solid crust underlain by an H2O-NH3 mushy layer is driven by the evolution of tidal heating, as Triton's orbital eccentricity evolves following its capture. The governing equations for tidal heating are solved using the propagator matrix method [6, 7], while the governing equation for the coupled crust-multiphase layer thermal evolution were numerically solved using a finite volume discretization. The results indicate that the existence of a subsurface ocean is strongly dependent on ammonia content as larger concentrations of ammonia influence liquidus temperature and density contrast between solid and liquid phases [8]. Preliminary results indicate that an ocean likely exists for compositions containing a relatively high percentage of ammonia for both early and late capture of the satellite. In contrast, the subsurface ocean freezes completely for lower ammonia content. [1] Brown, R. H., Kirk, R. L. (1994). Journal of Geophysical Research 99, 1965-981. [2] Prockter, L. M., Nimmo, F., Pappalardo, R. T. (2005). Geophysical Research Letters 32, L14202. [3] Ross, M. N., Schubert, G

Tungsten foil laminate for structural divertor applications - Joining of tungsten foils

NASA Astrophysics Data System (ADS)

Reiser, Jens; Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan; Mrotzek, Tobias; Hoffmann, Andreas; Armstrong, D. E. J.; Yi, Xiaoou

2013-05-01

This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

The influence of thermal inertia on temperatures and frost stability on Triton

NASA Technical Reports Server (NTRS)

Spencer, John R.; Moore, Jeffrey M.

1992-01-01

It is presently argued, in view of (1) a thermal inertia model for the surface of Triton which (like previous ones) predicts a monotonic recession of permanent N2 deposits toward the poles and very little seasonal N2 frost in the southern hemisphere, and (2) new spectroscopic evidence for nonvolatile CO2 on Triton's bright southern hemisphere, that much of that bright southern material is not N2. Such bright southern hemisphere volatiles may allow the formation of seasonal frosts, thereby helping to explain the observed spectroscopic changes of Triton during the last decade.

Polar Wander on Triton and Pluto Due to Volatile Migration

NASA Technical Reports Server (NTRS)

Rubincam, David Parry

2002-01-01

Polar wander may occur on Triton and Pluto because of volatile migration. Triton, with its low obliquity, can theoretically sublimate volatiles (mostly nitrogen) at the rate of approximately 10(exp 14) kilograms per year from the equatorial regions and deposit them at the poles. Assuming Triton to be rigid on the sublimation timescale, after approximately 10(exp 5) years the polar caps would become large enough to cancel the rotational flattening, with a total mass equivalent to a global layer approximately 120-250 m in depth. At this point the pole wanders about the tidal bulge axis, which is the line joining Triton and Neptune. Rotation about the bulge axis might be expected to disturb the leading side/trailing side cratering statistics. Because no such disturbance is observed, it may be that Triton's mantle viscosity is too high but its surface volatile inventory is too low to permit wander. On the other hand, its mantle viscosity might be low, so that any uncompensated cap load might be expected to wander toward the tidal bulge axis. In this case, the axis of wander passes through the equator from the leading side to the trailing side; rotation about this wander axis would not disturb the cratering statistics. Low-viscosity polar wander may explain the bright southern hemisphere: this is the pole which is wandering toward the equator. In any case the permanent polar caps may be geologically very young. Polar wander may possibly take place on Pluto, due to its obliquity oscillations and perihelion-pole geometry. However, Pluto is probably not experiencing any wander at present. The Sun has been shining strongly on the poles over the last half of the obliquity cycle, so that volatiles should migrate to the equator, stabilizing the planet against wander. Spacecraft missions to Triton and Pluto which measure the dynamical flattening could give information about the accumulation of volatiles at the poles. Such information is best obtained by measuring gravity and

Zonally averaged thermal balance and stability models for nitrogen polar caps on Triton

NASA Technical Reports Server (NTRS)

Stansberry, John A.; Lunine, J. I.; Porco, C. C.; Mcewen, A. S.

1990-01-01

Voyager four-color imaging data of Triton are analyzed to calculate the bolometric hemispheric albedo as a function of latitude and longitude. Zonal averages of these data have been incorporated into a thermal balance model involving insolation, reradiation, and latent heat of sublimation of N2 ice for the surface. The current average bolometric albedo of Triton's polar caps is 0.8, implying an effective temperature of 34.2 K and a surface pressure of N2 of 1.6 microbar for unit emissivity. This pressure is an order of magnitude lower than the surface pressure of 18 microbar inferred from Voyager data (Broadfoot et al., 1989; Conrath et al., 1989), a discrepancy that can be reconciled if the emissivity of the N2 on Triton's surface is 0.66. The model predicts that Triton's surface north of 15 deg N latitude is experiencing deposition of N2 frosts, as are the bright portions of the south polar cap near the equator. This result explains why the south cap covers nearly the entire southern hemisphere of Triton.

Micrometeorite penetration effects in gold foil

NASA Technical Reports Server (NTRS)

Hallgren, D. S.; Radigan, W.; Hemenway, C. L.

1976-01-01

Penetration structures revealed by a Skylab experiment dealing with exposure of single and double layers of 500-800 A thick gold foil to micrometeorites are examined. Examination of all double-layered gold foils revealed that particles producing holes of any type greater than 5 microns in diameter in the first foil break up into many fragments which in turn produce many more holes in the second foil. Evidence of an original particle is not found on any stainless steel plate below the foils, except in one instance. A precise relationship between the size of the event and the mass of the particle producing it could not be determined due to the extreme morphological variety in penetration effects. Fluxes from gold foil and crater experiments are briefly discussed.

Method for fabricating uranium foils and uranium alloy foils

DOEpatents

Hofman, Gerard L [Downers Grove, IL; Meyer, Mitchell K [Idaho Falls, ID; Knighton, Gaven C [Moore, ID; Clark, Curtis R [Idaho Falls, ID

2006-09-05

A method of producing thin foils of uranium or an alloy. The uranium or alloy is cast as a plate or sheet having a thickness less than about 5 mm and thereafter cold rolled in one or more passes at substantially ambient temperatures until the uranium or alloy thereof is in the shape of a foil having a thickness less than about 1.0 mm. The uranium alloy includes one or more of Zr, Nb, Mo, Cr, Fe, Si, Ni, Cu or Al.

The Effect of Journal Roughness and Foil Coatings on the Performance of Heavily Loaded Foil Air Bearings

NASA Technical Reports Server (NTRS)

Radil, Kevin C.; DellaCorte, Christopher

2001-01-01

Foil air bearing load capacity tests were conducted to investigate if a solid lubricant coating applied to the surface of the bearing's top foil can function as a break-in coating. Two foil coating materials, a conventional soft polymer film (polyimide) and a hard ceramic (alumina), were independently evaluated against as-ground and worn (run-in) journals coated with NASA PS304, a high-temperature solid lubricant composite coating. The foil coatings were evaluated at journal rotational speeds of 30,000 rpm and at 25 C. Tests were also performed on a foil bearing with a bare (uncoated) nickel-based superalloy top foil to establish a baseline for comparison. The test results indicate that the presence of a top foil solid lubricant coating is effective at increasing the load capacity performance of the foil bearing. Compared to the uncoated baseline, the addition of the soft polymer coating on the top foil increased the bearing load coefficient by 120% when operating against an as-ground journal surface and 85 percent against a run-in journal surface. The alumina coating increased the load coefficient by 40% against the as-ground journal but did not have any affect when the bearing was operated with the run-in journal. The results suggest that the addition of solid lubricant films provide added lubrication when the air film is marginal indicating that as the load capacity is approached foil air bearings transition from hydrodynamic to mixed and boundary lubrication.

Triton Southern Hemisphere

NASA Image and Video Library

1998-06-08

This polar projection from NASA Voyager 2 of Triton southern hemisphere provides a view of the southern polar cap and bright equatorial fringe. The margin of the cap is scalloped and ranges in latitude from +10 degrees to -30 degrees. The bright fringe is closely associated with the cap's margin; from it, diffuse bright rays extend north-northeast for hundreds of kilometers. The bright fringe probably consists of very fresh nitrogen frost or snow, and the rays consist of bright-fringe materials that were redistributed by north-moving Coriolis-deflected winds. http://photojournal.jpl.nasa.gov/catalog/PIA00423

Triton's Atmospheric Structure: What We Have Learned from Stellar Occultations and Prospects for the Future

NASA Astrophysics Data System (ADS)

Elliot, J. L.; Olkin, C. B.

1997-07-01

In 1993 we began a program for observing stellar occultations by Triton with the following objectives: (1) probe Triton's atmosphere in the microbar pressure region for comparison with models based on Voyager data (e.g. Strobel et al., Icarus 120, 266), (2) investigate the predicted seasonal changes in surface pressure (Spencer & Moore, Icarus 99, 261; Hansen & Paige, Icarus 99, 273) and (3) investigate spatial variability of the atmospheric structure. Observations have been successful for three stars, and the results are descibed by Olkin et al. (Icarus, in press) and Elliot et al. (Science, submitted). A large difference between the observations and models in the pressure and temperature at a radius of 1400 km (about 50 km altitude) may be due to seasonal change or inadequacy of the models. Triton's atmosphere has been found to be highly distorted from spherical symmetry, which has been interpreted as evidence for winds near the sonic velocity ( ~ 140 m s(-1) ). Based on current knowledge of Triton's atmosphere just described, our goals for future investigations of Triton's atmosphere are threefold: (i) map the central-flash with multiple chords in order to understand how Triton's atmosphere is distorted, (ii) obtain a light curve of greater S/N than we have at present in order to better establish Triton's temperature and pressure profiles so that present models based on Voyager data can be improved; and (iii) regularly probe Triton's atmosphere (annually if possible) in order to learn how its pressure changes with time. The prospects for observation of more high-quality Triton occultations are bright for the next three years (McDonald & Elliot, AJ 109, 1352), after which the Neptune system moves away from the galactic plane and the frequency of events diminishes. This work was supported, in part, by NASA Grants NAG5-3940 at MIT and NAG2-1078 at Lowell Observatory.

Restaurant Training Recipe At Triton College

ERIC Educational Resources Information Center

Quagliano, Joseph

1974-01-01

The successful restaurant training program at Triton College (Illinois) involves a broadly based, two-year curriculum offering practical training in nearly all the areas associated with a comprehensive food operation--management, food preparation, menu planning, nutrition, personnel vending, dining room service, and cost control. (Author/EA)

Triton - Scattering models and surface/atmosphere constraints

NASA Technical Reports Server (NTRS)

Thompson, W. Reid

1989-01-01

Modeling of Triton's spectrum indicates a bright scattering layer of optical depth tau about 3 overlying an optically deep layer of CH4 with high absorption and little scattering. UV absorption in the spectrum indicates tau about 0.3 of red-yellow haze, although some color may also arise from complex organics partially visible on the surface. An analysis of this and other (spectro)photometric evidence indicates that Triton most likely has a bright surface, which was partially visible in 1977-1980. Geometric albedo p = 0.62 + 0.18 or - 0.12 radius r = 1480 + or - 180 km, and temperature T = 48 + or - 6 K. With scattering optical depths of 0.3-3 and about 1-10 mb of N2, a Mars-like atmospheric density and surface visibility pertain.

Improved Simulation of the Pre-equilibrium Triton Emission in Nuclear Reactions Induced by Nucleons

NASA Astrophysics Data System (ADS)

Konobeyev, A. Yu.; Fischer, U.; Pereslavtsev, P. E.; Blann, M.

2014-04-01

A new approach is proposed for the calculation of non-equilibrium triton energy distributions in nuclear reactions induced by nucleons of intermediate energies. It combines models describing the nucleon pick-up, the coalescence and the triton knock-out processes. Emission and absorption rates for excited particles are represented by the pre-equilibrium hybrid model. The model of Sato, Iwamoto, Harada is used to describe the nucleon pick-up and the coalescence of nucleons from exciton configurations starting from (2p,1h) states. The contribution of the direct nucleon pick-up is described phenomenologically. Multiple pre-equilibrium emission of tritons is accounted for. The calculated triton energy distributions are compared with available experimental data.

Bonded foil pressure transducers

NASA Astrophysics Data System (ADS)

Daube, Bernie W.

The design of bonded-foil pressure transducers is discussed, with consideration given to individual components of both the electrical and the mechanical sections of the bonded-foil pressure transducers, as well as to the temperature control and the accuracy specification of these devices. Particular attention is given to applications of bonded foil pressure transducers, which include solid and liquid rocket engine testing for fuel and exhaust pressures, fuel and oil pressure monitoring on jet engines, and nuclear underground safety system pressure monitoring and nuclear test monitoring. A diagram of a transducer cutaway view is included.

Pitch jnd and the tritone paradox: The linguistic nexus

NASA Astrophysics Data System (ADS)

Safari, Kourosh

2002-11-01

Previous research has shown a connection between absolute pitch (the ability to name a specific pitch in the absence of any reference) and native competence in a tone language (Deutsch, 1990). In tone languages, tone is one of the features which determines the lexical meaning of a word. This study investigates the relationship between native competence in a tone language and the just noticeable difference of pitch. Furthermore, the tritone paradox studies have shown that subjects hear two tritones (with bell-shaped spectral envelopes) as either ascending or descending depending on their linguistic backgrounds (Deutsch, 1987). It is hypothesized that the native speakers of tone languages have a higher JND for pitch, and hear the two tones of the tritone paradox as ascending, whereas, native speakers of nontone languages hear them as descending. This study will indicate the importance of early musical training for the development of acute tone sensitivity. It will also underline the importance of language and culture in the way it shapes our musical understanding. The significance of this study will be in the areas of music education and pedagogy.

SQL/NF Translator for the Triton Nested Relational Database System

DTIC Science & Technology

1990-12-01

18as., Ohio .. 9~~ ~~ 1 4- AFIT/GCE/ENG/90D-05 SQL/Nk1 TRANSLATOR FOR THE TRITON NESTED RELATIONAL DATABASE SYSTEM THESIS Craig William Schnepf Captain...FOR THE TRITON NESTED RELATIONAL DATABASE SYSTEM THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technnlogy... systems . The SQL/NF query language used for the nested relationil model is an extension of the popular relational model query language SQL. The query

Boron stripper foils for particle accelerators

NASA Astrophysics Data System (ADS)

Zeisler, Stefan K.; Brigham, Michael; Kaur, Ishneet; Jaggi, Vinder

2018-05-01

Micromatter Technologies Inc., now located in Surrey B.C., Canada, is a worldwide supplier of pure and boron containing diamond-like carbon (DLC) stripper foils ranging from 10 nm to 10 μm. These foils are manufactured in-house using pulsed laser deposition. Continuing our research into novel production methods and alternative materials to be used as beam strippers for heavy elements and in particular for tandem particle accelerators, pure boron foils were prepared by laser plasma ablation of a disc shaped boron sputter target. Foil thickness between 10 nm to approximately 0.7 μm were achieved. The new boron foils showed considerably less stress, higher mechanical strength and better flexibility than comparable DLC films.

NMR of samples containing metal foils.

PubMed

Xiong, J; Lock, H; Tao, T; Keeler, C; Maciel, G E

1999-07-01

By using spool configurations of a sample containing aluminum foil, in which the axis of the spool is collinear with the RF coil axis, one can obtain high-quality 13C NMR spectra of static samples of organic material attached to the aluminum foil. By combining such a spool configuration (or, alternatively, analogous samples containing equivalent amounts of fine aluminum powder) with the magic-angle hopping (MAH) technique, one can achieve a high degree of isotropic averaging of the 13C spectrum. This opens to NMR techniques the study of a variety of samples containing macroscopic pieces of metal foils, e.g., thin films deposited on metal foils and electrochemical systems with species adsorbed on metal-foil electrodes.

Dynamics of a satellite and normalization around lagrangian points in the Neptune-Triton system

NASA Astrophysics Data System (ADS)

Yokoyama, T.; Stuchi, T. J.; Solórzano, C. R. H.; Corria, A. A.; Prado, A. F. B.; Winter, O. C.; Winter, S. M. G.; Sanchez, D. M.

Since a mission to Pluto-Charon is in progress a similar mission to Neptune-Triton system probably is just a matter of time Besides the interesting items listed in the Hammel s proposal to explore Neptune Hammel et al 2002 there are others very interesting points Triton is a very large satellite with M T M N approx 2 09 times 10 -4 where M T and M N are the masses of Triton and Neptune respectively Its current inclination with respect to Neptune s equator is about 157 345 0 This unusual high and retrograde inclination for a very large inner satellite makes this problem unique in our solar system Hammel et al 2002 also propose that a top priority in this mission should be a Neptune-Triton orbiter not just a flyby tour Therefore assuming a massless spacecraft orbiting Neptune-Triton system basically the system can be stated in terms of the classical restricted three body problem The new ingredient is the Neptune oblateness and the retrograde motion of Triton With some slight displacements the lagrangian equilibria points still exist as well as many of the properties of the classical problem In this work we first give an extensive numerical exploration in the case when the spacecraft orbits Triton considering Sun Neptune and its oblateness as disturbers In the plane bf a times bf I where bf a is the semi major axis and bf I is the inclination of the orbiter we give a plot of the stable regions where the massless can survive for thousand of years Retrograde and direct inclinations were

Passive Thermal Management of Foil Bearings

NASA Technical Reports Server (NTRS)

Bruckner, Robert J. (Inventor)

2015-01-01

Systems and methods for passive thermal management of foil bearing systems are disclosed herein. The flow of the hydrodynamic film across the surface of bearing compliant foils may be disrupted to provide passive cooling and to improve the performance and reliability of the foil bearing system.

Triton College Marketing Plan '85-'86.

ERIC Educational Resources Information Center

Fonte, Richard, Ed.; Leach, Ernie, Ed.

Prepared in response to shifts in the student body make-up and demographic changes in the school district, this report provides an in-depth analysis of environmental conditions faced by Triton College (Illinois) and presents a specific marketing plan developed in response to the identified trends. The first sections of the report focus on trends…

Triton - False Color of Cantaloupe Terrain

NASA Image and Video Library

1996-09-26

Voyager violet, green, and ultraviolet images of Triton were map projected into cylindrical coordinates and combined to produce this false color terrain map. Several compositionally distinct terrain and geologic features are portrayed. At center is a gray blue unit referred to as 'cantaloupe' terrain because of its unusual topographic texture. The unit appears to predate other units to the left. Immediately adjacent to the cantaloupe terrain, is a smoother unit, represented by a reddish color, that has been dissected by a prominent fault system. This unit apparently overlies a much higher albedo material, seen farther left. A prominent angular albedo boundary separates relatively undisturbed smooth terrain from irregular patches which have been derived from breakup of the same material. Also visible at the far left are diffuse, elongated streaks, which seem to emanate from circular, often bright centered features. The parallel streaks may represent vented particulate materials blown in the same direction by winds in Triton's thin atmosphere. The Voyager Mission was conducted by JPL for NASA's Office of Space Science and Applications. http://photojournal.jpl.nasa.gov/catalog/PIA00060

Rhenium-Foil Witness Cylinders

NASA Technical Reports Server (NTRS)

Knight, B. L.

1992-01-01

Cylindrical portion of wall of combustion chamber replaced with rhenium foil mounted on holder. Rhenium oxidizes without melting, indicating regions of excess oxidizer in combustion-chamber flow. Rhenium witness foils also useful in detecting excess oxygen and other oxidizers at temperatures between 2,000 and 3,600 degrees F in burner cores of advanced gas-turbine engines.

Psychoanalytic and musical ambiguity: the tritone in gee, officer krupke.

PubMed

Jaffee Nagel, Julie

2010-02-01

The poignant and timeless Broadway musical West Side Story is viewed from the standpoint of taking musical forms as psychoanalytic data. The musical configuration of notes called the tritone (or diabolus in musica) is taken as a sonic metaphor expressing ambiguity both in musical vocabulary and in mental life. The tritone, which historically and harmonically represents instability, is heard throughout the score and emphasizes the intrapsychic, interpersonal, and social dramas that unfold within and between the two gangs in West Side Story. Particular emphasis is given to the comic but exceedingly sober song Gee, Officer Krupke. Bernstein's sensitivity to the ambiguity and tension inherent in the tritone in West Side Story is conceptualized as an intersection of music theory and theories of mind; this perspective holds implications for clinical practice and transports psychoanalytic concepts from the couch to the Broadway stage and into the community to address the complexities of love, hate, aggression, prejudice, and violence. Ultimately, West Side Story cross-pollinates music and theater, as well as music and psychoanalytic concepts.

Utilization of Triton X-100 and polyethylene glycols during surfactant-mediated biodegradation of diesel fuel.

PubMed

Wyrwas, Bogdan; Chrzanowski, Łukasz; Ławniczak, Łukasz; Szulc, Alicja; Cyplik, Paweł; Białas, Wojciech; Szymański, Andrzej; Hołderna-Odachowska, Aleksandra

2011-12-15

The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t(1/2)=10.3h), compared to anaerobic conditions (t(1/2)=21.8h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the 'central fission' mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48-72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative planetary nitrogen atmospheres: Density and thermal structures of Pluto and Triton

NASA Astrophysics Data System (ADS)

Strobel, Darrell F.; Zhu, Xun

2017-07-01

Both atmospheres of Pluto and Neptune's largest satellite Triton have cold surfaces with surface gravitational accelerations and atmospheric surface pressures of comparable magnitude. To study their atmospheres we have updated Zhu et al. (2014) model for Pluto's atmosphere by adopting Voigt line profiles in the radiation module with the latest spectral database and extended the model to Triton's atmosphere by including additional parameterized heating due to the magnetospheric electron transport and energy deposition. The CH4 mixing ratio profiles play central roles in differentiating the atmospheres of Pluto and Triton. On Pluto the surface CH4 mole fraction is in the range of 0.3-0.8%, sufficiently high to ensure that it is well mixed in the lower atmosphere and not subject to photochemical destruction. Near the exobase CH4 attains comparable density to N2 due to gravitational diffusive separation and escapes at 500 times the N2 rate (= 1 × 1023 N2 s-1). In Triton's atmosphere, the surface CH4 mole fraction is on the order of 0.015%, sufficiently low to ensure that it is photochemically destroyed irreversibly in the lower atmosphere and that N2 remains the major species, even at the exobase. With solar EUV power only, Triton's upper thermosphere is too cold and magnetospheric heating, approximately comparable to the solar EUV power, is needed to bring the N2 tangential column number density in the 500-800 km range up to values derived from the Voyager 2 UVS observations (Broadfoot et al., 1989). Due to their cold exobase temperatures relative to the gravitational potential energy wells that N2 resides in, atmospheric escape from Triton and Pluto is not dominated by N2 Jeans escape but by CH4 from Pluto and H, C, N and H2 from Triton. The atmospheric thermal structure near the exobase is sensitive to the atmospheric escape rate only when it is significantly greater than 2 × 1027 amu s-1, above which enhanced Jeans escape and larger radial velocity adiabatically

Extended foil capacitor with radially spoked electrodes

DOEpatents

Foster, James C.

1990-01-01

An extended foil capacitor has a conductive disk electrically connected in oncrushing contact to the extended foil. A conductive paste is placed through spaces between radial spokes on the disk to electrically and mechanically connect the extended foil to the disk.

Carbon Stripper Foils Used in the Los Alamos PSR

NASA Astrophysics Data System (ADS)

Borden, M.; Plum, M. A.; Sugai, I.

1997-05-01

Carbon stripper foils produced by the modified controlled ACDC arc discharge method (mCADAD) at the Institute for Nuclear Study by Dr. Isao Sugai have been tested and used for high current 800-MeV beam production in the Proton Storage Ring (PSR) since 1993. Two approximately 110 μg/cm2 foils are sandwiched together to produce an equivalent 220 μg/cm^2 foil. The combined foil is supported by 4-5 μm diameter carbon fibers attached to an aluminum frame. These foils have survived as long as five months during PSR normal beam production of near 70 μA on target average current. Typical life-times of other foils vary from seven to fourteen days with lower on-target average current. Beam loss data also indicate that Sugai's foils have slower shrinkage rates than other foils. Equipment has been assembled and used to produce foils by the mCADAD method at Los Alamos. These foils will be tested during 1997 operation.

The Prediction and Observation of the 1997 July 18 Stellar Occultation by Triton: More Evidence for Distortion and Increasing Pressure in Triton's Atmosphere

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Person, M. J.; McDonald, S. W.; Buie, M. W.; Dunham, E. W.; Millis, R. L.; Nye, R. A.; Olkin, C. B.; Wasserman, L. H.; Young, L. A.

2000-01-01

We used CCD (charge coupled device) astrometric data to predict where the occultation path of the star Tr 176 was located, on July 18, 1997. It could be seen from northern Australia and the southern section of North America. We set up an array of portable and mixed telescopes which had high-speed photometric equipment to observe the occultation. Goals included the following: (1) mapping the central flash; (2) obtaining light curves for the signal-to-noise ratio; (3) acquiring light curves from Triton's disk. We combined these with data from others to find the radius and geometry of the half-light surface of the atmosphere, as well as the equivalent-isothermal temperature latitudes below the occultation on Triton.

Tidal interaction: A possible explanation for geysers and other fluid phenomena in the Neptune-Triton system

NASA Technical Reports Server (NTRS)

Kelly, W. D.; Wood, C. L.

1993-01-01

Discovery of geyser-like plumes on the surface of Triton was a highlight of Voyager 2's passage through the Neptune planetary system. Remarkable as these observations were, they were not entirely without precedent. Considering the confirmed predictions for the 1979 Voyager Jovian passage, it was logical to consider other solar system bodies beside Io where tidal effects could be a significant factor in surface processes. It was our intuition that the Neptune-Triton gravitational bond acting at high inclination to the Neptune equator and the fact that Neptune was a fluid body was significant oblateness would produce tidal and mechanical forces that could be transformed into thermal energy vented on Triton's surface. Prior to the Voyager flyby, others have noted that capture and evolution of Triton's orbit from extreme eccentricity to near circular state today would have resulted in significant tidal heating, but these analysts disregard current day forces. Our calculations indicate that the time varying forces between Neptune-Triton fall midway between those exerted in the Earth-Moon and Jupiter-Io systems, and considering the low level of other energy inputs, this source of internal energy should not be ignored when seeking an explanation for surface activity. In each planet-satellite case, residual or steady-state eccentricity causes time-varying stresses on internal satellite strata. In the case of Jupiter the residual eccentricity is due largely to Galilean satellite interactions, particularly Io-Europa, but in the case of Neptune-Triton, it is the effect of Triton's inclined orbit about an oblate primary.

Geographic Distribution of N2, CH4, CO2, and H2O Ices on Triton from Near-IR Spectroscopic Monitoring

NASA Astrophysics Data System (ADS)

Grundy, W. M.; Young, L. A.; Young, E. F.; Buie, M. W.; Spencer, J. R.

2004-11-01

We present new 0.8 to 2.4 μ m spectral observations of Neptune's satellite Triton, obtained at IRTF\\slash SpeX between 2001 and 2004 as part of an ongoing search for time-variable phenomena associated with Triton's seasonal volatile transport processes, and also perhaps with reported shorter-term "reddening" events. The ability to detect spectral changes on these time scales depends critically on accurate characterization of any cyclic variations resulting from Triton's 5.877 day rotation period. We will report on our observations of periodic variations of Triton's near-IR absorption bands of N2, CH4, and H2O ices, but not of CO2 ice, in this initial stage of our Triton monitoring program. The observed variations (or lack thereof) give an indication of how these four ice species are distributed in longitude. The most heterogeneously distributed ice is N2, which shows nearly twice as much absorption on Triton's Neptune-facing hemisphere as on the anti-Neptune hemisphere. Comparison with Voyager-era, visual wavelength imaging of Triton's surface suggest that the observed N2 ice is concentrated on low-latitude regions of Triton's polar cap, which are predominantly located on the Neptune-facing hemisphere. Non-volatile H2O ice seems to be slightly concentrated on Triton's leading hemisphere. Despite being highly diluted in N2 ice, the longitudinal distribution of Triton's CH4 ice differs from that of Triton's N2 ice, being slightly concentrated on Triton's trailing hemisphere. Triton's CO2 ice shows the least longitudinal variation, suggesting that it is either very uniformly distributed or that it is confined to high latitudes. This work was supported by NASA's Planetary Astronomy and Planetary Geology &\\ Geophysics programs, and by NSF's Planetary Astronomy program. \\hangindent=0.3truein Grundy, W.M., and L.A. Young (2004) Near infrared spectral monitoring of Triton with IRTF\\slash SpeX I: Establishing a baseline. Icarus (in press).

High strain rate metalworking with vaporizing foil actuator: Control of flyer velocity by varying input energy and foil thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vivek, A., E-mail: vivek.4@osu.edu; Hansen, S. R.; Daehn, Glenn S.

2014-07-15

Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Dopplermore » velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.« less

Neptune's Triton: A moon rich in dry ice and carbon

NASA Technical Reports Server (NTRS)

Prentice, A. J. R.

1989-01-01

The encounter of the spacecraft Voyager 2 with Neptune and its large satellite Triton in August 1989 will provide a crucial test of ideas regarding the origin and chemical composition of the outer solar system. In this pre-encounter publication, the possibility is quantified that Titron is a captured moon which, like Pluto and Charon, originally condensed as a major planetesimal within the gas ring that was shed by the contracting protosolar cloud at Neptune's orbit. Ideas of supersonic convective turbulence are used to compute the gas pressure, temperature and rat of catalytic synthesis of CH4, CO2, and C(s) within the protosolar cloud, assuming that all C is initially present as CO. The calculations lead to a unique composition for Triton, Pluto, Charon: each body consists of, by mass, 18 1/2 percent solid CO2 ice, 4 percent graphite, 1/2 percent CH4 ice, 29 percent methanated water ice and 48 percent of anhydrous rock. This mix has a density consistent with that of the Pluto-Charon system and yields a predicted mean density for Triton of 2.20 + or - 0.5 g/cu cm, for satellite radius equal to 1,750 km.

Collodion-reinforcement and plasma-cleaning of target foils

NASA Astrophysics Data System (ADS)

Stoner, John O.

2002-03-01

The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed.

A new modal-based approach for modelling the bump foil structure in the simultaneous solution of foil-air bearing rotor dynamic problems

NASA Astrophysics Data System (ADS)

Bin Hassan, M. F.; Bonello, P.

2017-05-01

Recently-proposed techniques for the simultaneous solution of foil-air bearing (FAB) rotor dynamic problems have been limited to a simple bump foil model in which the individual bumps were modelled as independent spring-damper (ISD) subsystems. The present paper addresses this limitation by introducing a modal model of the bump foil structure into the simultaneous solution scheme. The dynamics of the corrugated bump foil structure are first studied using the finite element (FE) technique. This study is experimentally validated using a purpose-made corrugated foil structure. Based on the findings of this study, it is proposed that the dynamics of the full foil structure, including bump interaction and foil inertia, can be represented by a modal model comprising a limited number of modes. This full foil structure modal model (FFSMM) is then adapted into the rotordynamic FAB problem solution scheme, instead of the ISD model. Preliminary results using the FFSMM under static and unbalance excitation conditions are proven to be reliable by comparison against the corresponding ISD foil model results and by cross-correlating different methods for computing the deflection of the full foil structure. The rotor-bearing model is also validated against experimental and theoretical results in the literature.

Method of forming a thin unbacked metal foil

DOEpatents

Duchane, David V.; Barthell, Barry L.

1984-01-01

In a method of forming a thin (<2 .mu.m) unbacked metal foil having a desired curviplanar shape, a soluble polymeric film, preferably comprising polyvinyl alcohol, is formed on a supporting structure having a shape that defines the desired shape of the foil product. A layer of metal foil is deposited onto one side of the soluble film, preferably by vacuum vapor deposition. The metallized film is then immersed in a suitable solvent to dissolve the film and thereby leave the metal foil as an unbacked metal foil element mounted on the supporting structure. Aluminum foils less than 0.2 .mu.m (2,000 .ANG.) thick and having an areal density of less than 54 .mu.g/cm.sup.2 have been obtained.

The transonic multi-foil Augmentor-Wing

NASA Technical Reports Server (NTRS)

Farbridge, J. E.; Smith, R. C.

1977-01-01

The paper describes the development of a transonic blown multi-foil Augmentor-Wing airfoil section that has a thickness/chord (t/c) value of 0.18. In comparison with an unblown single-foil supercritical section of the same overall t/c the new multi-foil section is characterized by an increased drag rise Mach number, increased buffet boundaries, and a reduction in 'effective' drag due to blowing. Potential advantages of the Augmentor-Wing are considered and the testing of three high-speed models in a trisonic pressurized wind tunnel (possessing a two-dimensional transonic insert) is discussed. The data indicate that a very thick wing is feasible since separations toward the rear of the main foil can be controlled both by shroud location and augmentor blowing.

The Impact of Developmental Education at Triton College.

ERIC Educational Resources Information Center

Chand, Sunil

1985-01-01

Describes the following aspects of the Developmental Education Program at Triton College: student placement, courses, faculty selection, reading and writing instruction, mathematics instruction, the Learning Assistance Center (LAC), LAC tutoring, LAC special projects, LAC management, special needs assistance program for disabled students, and…

Infrared spectoscopy of Triton and Pluto ice analogs: The case for saturated hydrocarbons

NASA Technical Reports Server (NTRS)

Bohn, Robert B.; Sandford, Scott A.; Allamandola, Louis J.; Cruikshank, Dale P.

1994-01-01

The infrared transmission spectra and photochemical behavior of various organic compounds isolated in solid N2 ices, appropriate for applications to Triton ad Pluto, are presented. It is shown that excess absorption in the surface spectra of Triton and Pluto, i.e., absorption not explained by present models incorporating molecules already identified on these bodies (N2, CH4, CO, and CO2), that starts near 4450/cm (2.25 microns) and extends to lower frequencies, may be due to alkanes (C(n)H(2n+2)) and related molecules frozen in the nitrogen. Branched and linear alkanes may be responsible. Experiments in which the photochemstry of N2: CH4 and N2: CH4: CO ices was explored demonsrtrate that the surface ices of Triton and Pluto may contain a wide variety of additional species containing H, C, O, and N. Of these, the reactive molecule diazomethane, CH2N2, is particularly important since it may be largely responsible for the synthesis of larger alkanes from CH4 and other small alkanes. Diazomethane would also be expected to drive chemical reactions involving organics in the surface ices of Triton and Pluto toward saturation, i.e., to reduce multiple CC bonds. The positions and intrinsic strengths (A values) of many of the infrared absorption bands of N2 matrix-isolated molecules of relevance to Triton and Pluto have also been determined. These can be used to aid in their search and to place constraints on their abundances.

Resistence seam welding thin copper foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollar, D.L. Jr.

1991-02-01

Use of flat flexible circuits in the electronics industry is expanding. The term flexible circuits'' is defined here as copper foil which has been bonded to an insulating film such as Kapton film. The foil is photo processed to produce individual circuit paths similar to printed circuit boards. Another insulating film is laminated over the conductors to complete the flexible circuit. Flexible circuits, like multiwire cables, are susceptible to electromagnetic radiation (EMR) interference. On multiwire cables the interference problem is mitigated by adding a woven wire braid shielding over the conductors. Shielding on flexible circuits is accomplished by enclosing themore » circuits in a copper foil envelope. However, the copper foil must be electrically sealed around the flexcircuit to be effective. Ultimately, a resistance seam welding process and appropriate equipment were developed which would provide the required electrical seal between two layers of 2-oz (0.0028-inch thick) copper foil on a 1.1-inch wide, 30-inch long, 0.040-inch thick flexible circuit. 4 refs., 19 figs.« less

FOIL ELEMENT FOR NUCLEAR REACTOR

DOEpatents

Noland, R.A.; Walker, D.E.; Spinrad, B.I.

1963-07-16

A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

The Thermal Structure of Triton's Atmosphere: Results from the 1993 and 1995 Occultations

NASA Astrophysics Data System (ADS)

Olkin, C. B.; Elliot, J. L.; Hammel, H. B.; Cooray, A. R.; McDonald, S. W.; Foust, J. A.; Bosh, A. S.; Buie, M. W.; Millis, R. L.; Wasserman, L. H.; Dunham, E. W.; Young, L. A.; Howell, R. R.; Hubbard, W. B.; Hill, R.; Marcialis, R. L.; McDonald, J. S.; Rank, D. M.; Holbrook, J. C.; Reitsema, H. J.

1997-09-01

This paper presents new results about Triton's atmospheric structure from the analysis of all ground-based stellar occultation data recorded to date, including one single-chord occultation recorded on 1993 July 10 and nine occultation lightcurves from the double-star event on 1995 August 14. These stellar occultation observations made both in the visible and in the infrared have good spatial coverage of Triton, including the first Triton central-flash observations, and are the first data to probe the altitude level 20-100 km on Triton. The small-planet lightcurve model of J. L. Elliot and L. A. Young (1992,Astron. J.103,991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude, indicating that Triton's atmosphere is spherically symmetric at ∼50-km altitude to within the error of the measurements; however, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (∼20-km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 ± 1 K and the atmospheric pressure at 1400-km radius (∼50-km altitude) is 1.4 ± 0.1 μbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (D. F. Strobel, X. Zhu, M. E. Summers, and M. H. Stevens, 1996,Icarus120,266-289). The atmospheric temperature from the occultation is 5 K colder than that predicted by the model and the observed pressure is a factor of 1.8 greater than the model. In our opinion, the disagreement in temperature and pressure is probably due to modeling problems at the microbar level, since measurements at this level have not previously been made. Alternatively, the difference could be due to seasonal change in Triton's atmospheric structure.

Classroom Foils

ERIC Educational Resources Information Center

Pafford, William N.

1970-01-01

Aluminum foil, because of its characteristics, can be used for many elementary science activities: demonstrating Archimedes Principle, how to reduce cohesion, reflection and mirror effect, fuse action, condensation, friction, and as containers and barriers. (BR)

Technical Development Path for Gas Foil Bearings

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher

2016-01-01

Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

Structure of Triton's atmosphere from the occultation of Tr176

NASA Astrophysics Data System (ADS)

Sicardy, B.; Mousis, O.; Beisker, W.; Hummel, E.; Hubbard, W. B.; Hill, R.; Reitsema, H. J.; Anderson, P.; Ball, L.; Downs, B.; Hutcheon, S.; Moy, M.; Nielsen, G.; Pink, I.; Walters, R.

1998-09-01

The occultation of the star Tr176 by Triton (Mc Donald & Elliot, AJ 109, 1352, 1995) was observed on 18 July 1997 from three stations in Queensland, Australia (Bundaberg, Ducabrook and Lochington) and one station in Texas, USA (Brownsville). All observations were made with CCD (no filter) and with portable C14 telescopes, except at Bundaberg, where a fixed 48-cm telescope was used. Time sampling rate ranges from 0.33 sec (Bundaberg) to 0.66 sec (Ducabrook and Lochington), with the intermediate value 0.5 sec at Brownsville. Isothermal fits were performed to the lightcurves in order to determine the isothermal temperature, T_iso, and the radius at half-level, R_{1/2}, of Triton's atmosphere (assumed to be composed of pure N_2). Considering the level of noise, we cannot detect any departure from isothermal profiles, and we do not see any deviations from spherical shape. A global fit yields T_iso = 53.7 +/- 2 K and R_{1/2} = 1456 +/- 3 km. We also derive the pressure at 1400 km: p1400 = 1.9 +/- 0.3 mu bars. We will discuss these results and compare them with previous works obtained by Voyager teams from the 1989 observations, and by Olkin et al. (Icarus 129, 178, 1997), who analyze two Triton occultations observed in July 1993 (Tr60) and August 1995 (Tr148). We observe a general increase of pressure at 1400 km, since Olkin et al. derive p1400 = 1.4 +/- 0.1 mu bars from the Tr148 event. This result is actually confirmed by a recent work by Elliot et al., (Nature 393, 765 1998), who note a global warming on Triton, based in particular on a new HST occultation observation in November 1997 (Tr180).

Foil Gas Thrust Bearings for High-Speed Turbomachinery

NASA Technical Reports Server (NTRS)

Edmonds, Brian; DellaCorte, Christopher; Dykas, Brian

2010-01-01

A methodology has been developed for the design and construction of simple foil thrust bearings intended for parametric performance testing and low marginal costs, supporting continued development of oil-free turbomachinery. A bearing backing plate is first machined and surface-ground to produce flat and parallel faces. Partial-arc slots needed to retain the foil components are then machined into the plate by wire electrical discharge machining. Slot thicknesses achievable by a single wire pass are appropriate to accommodate the practical range of foil thicknesses, leaving a small clearance in this hinged joint to permit limited motion. The backing plate is constructed from a nickel-based superalloy (Inconel 718) to allow heat treatment of the entire assembled bearing, as well as to permit hightemperature operation. However, other dimensionally stable materials, such as precipitation-hardened stainless steel, can also be used for this component depending on application. The top and bump foil blanks are cut from stacks of annealed Inconel X-750 foil by the same EDM process. The bump foil has several azimuthal slits separating it into five individual bump strips. This configuration allows for variable bump spacing, which helps to accommodate the effects of the varying surface velocity, thermal crowning, centrifugal dishing, and misalignment. Rectangular tabs on the foil blanks fit into the backing plate slots. For this application, a rather traditional set of conventionally machined dies is selected, and bump foil blanks are pressed into the dies for forming. This arrangement produces a set of bump foil dies for foil thrust bearings that provide for relatively inexpensive fabrication of various bump configurations, and employing methods and features from the public domain.

Characterization of laser-cut copper foil X-pinches

NASA Astrophysics Data System (ADS)

Collins, G. W.; Valenzuela, J. C.; Hansen, S. B.; Wei, M. S.; Reed, C. T.; Forsman, A. C.; Beg, F. N.

2016-10-01

Quantitative data analyses of laser-cut Cu foil X-pinch experiments on the 150 ns quarter-period, ˜250 kA GenASIS driver are presented. Three different foil designs are tested to determine the effects of initial structure on pinch outcome. Foil X-pinch data are also presented alongside the results from wire X-pinches with comparable mass. The X-ray flux and temporal profile of the emission from foil X-pinches differed significantly from that of wire X-pinches, with all emission from the foil X-pinches confined to a ˜3 ns period as opposed to the delayed, long-lasting electron beam emission common in wire X-pinches. Spectroscopic data show K-shell as well as significant L-shell emission from both foil and wire X-pinches. Fits to synthetic spectra using the SCRAM code suggest that pinching foil X's produced a ˜1 keV, ne ≥ 1023 cm-3 plasma. The spectral data combined with the improved reliability of the source timing, flux, and location indicate that foil X-pinches generate a reproducible, K-shell point-projection radiography source that can be easily modified and tailored to suit backlighting needs across a variety of applications.

Pu-ZR Alloy high-temperature activation-measurement foil

DOEpatents

McCuaig, Franklin D.

1977-08-02

A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron flux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

Producing carbon stripper foils containing boron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoner, J. O. Jr.

2012-12-19

Parameters being actively tested by the accelerator community for the purpose of extending carbon stripper foil lifetimes in fast ion beams include methods of deposition, parting agents, mounting techniques, support (fork) materials, and inclusion of alloying elements, particularly boron. Specialized production apparatus is required for either sequential deposition or co-deposition of boron in carbon foils. A dual-use vacuum evaporator for arc evaporation of carbon and electron-beam evaporation of boron and other materials has been built for such development. Production of both carbon and boron foils has begun and improvements are in progress.

Interactions of Triton X-100 with sphingomyelin and phosphatidylcholine monolayers: influence of the cholesterol content.

PubMed

Abi-Rizk, Georges; Besson, Françoise

2008-10-15

The presence of microdomains, called lipid rafts, in biological membranes is usually explained by lateral segregation between specific lipids and proteins. These rafts present similarities with the membrane domains isolated by their non-ionic detergent-resistance at 4 degrees C. They are enriched in sphingomyelin and cholesterol as compared with the outer leaflet of eukaryotic cell membranes. To understand the role played by the lipids enriched in rafts in their resistance to solubilization by detergents, the interactions between these lipids and the non-ionic detergent Triton X-100 were studied by using different lipid monolayers at the air-water interface. The influence of Triton X-100 on the Langmuir isotherms (i.e. surface pressure/area isotherms) of monolayers containing sphingomyelin and cholesterol at different mole ratios was analyzed and the results were compared with the influence of Triton X-100 on monolayers containing a phosphatidylcholine bearing a saturated and an unsaturated fatty acid (i.e. palmitoyloleylphosphatidylcholine) and cholesterol. This phosphatidylcholine was chosen since the phosphatidylcholines present in rafts isolated from bovine kidney could contain about 50% of saturated fatty acids. Triton X-100 induces an increase in the condensing effect observed as compared with ideal mixture of phospholipid/cholesterol. Triton X-100-induced changes in the morphology of the monolayers were visualized by Brewster angle microscopy, which confirmed the differences of behavior observed by analyzing the isotherms.

Producing Foils From Direct Cast Titanium Alloy Strip

NASA Technical Reports Server (NTRS)

Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

1996-01-01

This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

A Preliminary Foil Gas Bearing Performance Map

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

2006-01-01

Recent breakthrough improvements in foil gas bearing load capacity, high temperature tribological coatings and computer based modeling have enabled the development of increasingly larger and more advanced Oil-Free Turbomachinery systems. Successful integration of foil gas bearings into turbomachinery requires a step wise approach that includes conceptual design and feasibility studies, bearing testing, and rotor testing prior to full scale system level demonstrations. Unfortunately, the current level of understanding of foil gas bearings and especially their tribological behavior is often insufficient to avoid developmental problems thereby hampering commercialization of new applications. In this paper, a new approach loosely based upon accepted hydrodynamic theory, is developed which results in a "Foil Gas Bearing Performance Map" to guide the integration process. This performance map, which resembles a Stribeck curve for bearing friction, is useful in describing bearing operating regimes, performance safety margins, the effects of load on performance and limiting factors for foil gas bearings.

Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

NASA Technical Reports Server (NTRS)

Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

2010-01-01

An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

A Microfabricated Involute-Foil Regenerator for Stirling Engines

NASA Technical Reports Server (NTRS)

Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Qiu, Songgang

2007-01-01

A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C

A Microfabricated Involute-Foil Regenerator for Stirling Engines

NASA Technical Reports Server (NTRS)

Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terry; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Wood, Gary;

Infrared spectroscopy of Triton and Pluto ice analogs: the case for saturated hydrocarbons.

PubMed

Bohn, R B; Sandford, S A; Allamandola, L J; Cruikshank, D P

1994-09-01

The infrared transmission spectra and photochemical behavior of various organic compounds isolated in solid N2 ices, appropriate for applications to Triton and Pluto, are presented. It is shown that excess absorption in the surface spectra of Triton and Pluto, i.e., absorption not explained by present models incorporating molecules already identified on these bodies (N2, CH4, CO, and CO2), that starts near 4450 cm-1 (2.25 micrometers) and extends to lower frequencies, may be due to alkanes (C(n)H2n+2) and related molecules frozen in the nitrogen. Branched and linear alkanes may be responsible. Experiments in which the photochemistry of N2:CH4 and N(2):CH4:CO ices was explored demonstrate that the surface ices of Triton and Pluto may contain a wide variety of additional species containing H, C, O, and N. Of these, the reactive molecule diazomethane, CH2N2, is particularly important since it may be largely responsible for the synthesis of larger alkanes from CH4 and other small alkanes. Diazomethane would also be expected to drive chemical reactions involving organics in the surface ices of Triton and Pluto toward saturation, i.e., to reduce multiple CC bonds. The positions and intrinsic strengths (A values) of many of the infrared absorption bands of N2 matrix-isolated molecules of relevance to Triton and Pluto have also been determined. These can be used to aid in their search and to place constraints on their abundances. For example, using these A values the abundance ratios CH4/N2 approximately 1.3 x 10(-3), C2H4/N2 < or = 9.5 x 10(-7) and H2CO/N2 < or = 7.8 x 10(-7) are deduced for Triton and CH4/N2 approximately 3.1 x 10(-3), C2H4/N2 < or = 4.1 x 10(-6), and H2CO/N2 < or = 5.2 x 10(-6) deduced for Pluto. The small amounts of C2H4 and H2CO in the surface ices of these bodies are in disagreement with the large abundances expected from many theoretical models.

Methods of making metallic glass foil laminate composites

DOEpatents

Vianco, P.T.; Fisher, R.W.; Hosking, F.M.; Zanner, F.J.

1996-08-20

A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone. 6 figs.

Methods of making metallic glass foil laminate composites

DOEpatents

Vianco, Paul T.; Fisher, Robert W.; Hosking, Floyd M.; Zanner, Frank J.

1996-01-01

A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone.

Explosion of thin aluminum foils in air

NASA Astrophysics Data System (ADS)

Baksht, R.; Pokryvailo, A.; Yankelevich, Y.; Ziv, I.

2004-12-01

An inductive-based power supply (240μH, 50kA) was used for the investigation of the foil explosion process in the time range of 0.05msfoil current for these experiments was set between 10kA and 27kA. The foil thickness was 10μm and its length was 5cm. Images of the exploding foil captured by a fast framing camera show that the radiation of the exploding foil discharge starts on the voltage rise. The peak voltage Vpeak decreases with an increasing time to explosion and a decreasing current density: Vpeak=2.8kV at j =9.1MA/cm2 and Vpeak=1.75kV at j =5.3MA/cm2. A phenomenological model was suggested for the experimental data interpretations. Contrary to the previous model, we assume that the breakdown initiates with cathode spots instead of a breakdown by a bulk discharge. We suggest that the plasma appearance is related to the ejection of a metal vapor during the metal boiling. The high temperature of the vapor permits ignition of the cathode spots even at a low electric field. It results in the arcing in the metal vapor and bypassing the liquid pieces of the foil.

ICE MINERALOGY ACROSS AND INTO THE SURFACES OF PLUTO, TRITON, AND ERIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tegler, S. C.; Grundy, W. M.; Olkin, C. B.

We present three near-infrared spectra of Pluto taken with the Infrared Telescope Facility and SpeX, an optical spectrum of Triton taken with the MMT and the Red Channel Spectrograph, and previously published spectra of Pluto, Triton, and Eris. We combine these observations with a two-phase Hapke model and gain insight into the ice mineralogy on Pluto, Triton, and Eris. Specifically, we measure the methane-nitrogen mixing ratio across and into the surfaces of these icy dwarf planets. In addition, we present a laboratory experiment that demonstrates it is essential to model methane bands in spectra of icy dwarf planets with twomore » methane phases-one highly diluted by nitrogen and the other rich in methane. For Pluto, we find bulk, hemisphere-averaged, methane abundances of 9.1% {+-} 0.5%, 7.1% {+-} 0.4%, and 8.2% {+-} 0.3% for sub-Earth longitudes of 10 Degree-Sign , 125 Degree-Sign , and 257 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds these small differences are statistically significant. For Triton, we find bulk, hemisphere-averaged, methane abundances of 5.0% {+-} 0.1% and 5.3% {+-} 0.4% for sub-Earth longitudes of 138 Degree-Sign and 314 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds the differences are not statistically significant. For Eris, we find a bulk, hemisphere-averaged, methane abundance of 10% {+-} 2%. Pluto, Triton, and Eris do not exhibit a trend in methane-nitrogen mixing ratio with depth into their surfaces over the few centimeter range probed by these observations. This result is contrary to the expectation that since visible light penetrates deeper into a nitrogen-rich surface than the depths from which thermal emission emerges, net radiative heating at depth would drive preferential sublimation of nitrogen leading to an increase in the methane abundance with depth.« less

Foil bearings

NASA Astrophysics Data System (ADS)

Elrod, David A.

1993-11-01

The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

Nitrogen airglow sources - Comparison of Triton, Titan, and earth

NASA Technical Reports Server (NTRS)

Strobel, Darrell F.; Meier, R. R.; Summers, Michael E.; Strickland, Douglas J.

1991-01-01

The individual contributions of direct solar excitation, photoelectron excitation, and magnetospheric electron excitation of Triton and Titan airglow observed by the Voyager Ultraviolet Spectrometer (UVS) are quantified. The principal spectral features of Triton's airglow are shown to be consistent with precipitation of magnetospheric electrons with power dissipation about 500 million W. Solar excitation rates of the dominant N2 and N(+) emission features are factors of 2-7 weaker than magnetospheric electron excitation. On Titan, the calculated disk center and bright limb N(+) 1085 A intensities due to solar excitation agree with observed values, while the 970 A feature is mostly N21 c5 band emission. The calculated LBH intensity by photoelectrons suggests that magnetospheric electrons play a minor role in Titan's UV airglow. On earth, solar/photoelectron excitation explains the observed N(+) 1085 A and LBH intensites and accounts for only 40 percent of the N(+) 916 A intensity.

Force Generation by Flapping Foils

NASA Astrophysics Data System (ADS)

Bandyopadhyay, P. R.; Donnelly, M.

1996-11-01

Aquatic animals like fish use flapping caudal fins to produce axial and cross-stream forces. During WW2, German scientists had built and tested an underwater vehicle powered by similar flapping foils. We have examined the forces produced by a pair of flapping foils. We have examined the forced produced by a pair of flapping foils attached to the tail end of a small axisymmetric cylinder. The foils operate in-phase (called waving), or in anti-phase (called clapping). In a low-speed water tunnel, we have undertaken time-dependent measurements of axial and cross-stream forces and moments that are exerted by the vortex shedding process over the entire body. Phase-matched LDV measurements of vorticity-velocity vectors, as well as limited flow visualization of the periodic vortex shedding process have also been carried out. The direction of the induced velocity within a pair of shed vortices determines the nature of the forces produced, viz., thrust or drag or cross-stream forces. The clapping mode produces a widely dispersed symmetric array of vortices which results in axial forces only (thrust and rag). On the other hand, the vortex array is staggered in the waving mode and cross-stream (maneuvering) forces are then generated.

Pu-Zr alloy for high-temperature foil-type fuel

DOEpatents

McCuaig, Franklin D.

1977-01-01

A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron reflux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

[The polymorphism and distribution of B chromosomes in germline and somatic cells of Tscherskia triton de Winton (Rodentia, Cricetinae)].

PubMed

Borisov, Iu M

2012-05-01

The karyotypes of 13 greater long-tailed hamsters (Tscherskia triton de Winton, 1899) (eight males and five females) from Primorskii krai (Russia), including six males and one female from the vicinity of the city of Ussuriisk and two males and four females from the vicinity of the village of Pogranichnyi, have been studied. The karyotypes of five males (four from the vicinity of Ussuriisk and one from the vicinity of Pogranichnyi) have been found to contain one or two small acrocentric B chromosomes each. In males with B chromosomes, each germline cell contains one or two B chromosomes. The proportion of somatic cells carrying B chromosomes varies from 34.9 to 55.9% in these males. Karyological study of a total of 45 Tscherskia triton (30 males and 15 females) from Primorskii krai has been performed, B chromosomes being found in only five males (11.1%). In T. triton populations of Korea and China, also only a few animals have been found to carry one or two B chromosomes. The greater long-tailed hamster belongs to the monotypic genus Tscherskia; the animals described earlier under the names T. (Cricettilus) triton albipes Ognev, 1914 and T. (Cricettilus) triton nestor Thomas, 1907 belong to the only species in the genus, T. triton de Winton, 1899.

Differential solubilization of inner plasma membrane leaflet components by Lubrol WX and Triton X-100.

PubMed

Delaunay, Jean-Louis; Breton, Michelyne; Trugnan, Germain; Maurice, Michèle

2008-01-01

A commonly-used method for analysing raft membrane domains is based on their resistance to extraction by non-ionic detergents at 4 degrees C. However, the selectivity of different detergents in defining raft membrane domains has been questioned. We have compared the lipid composition of detergent-resistant membranes (DRMs) obtained after Triton X-100 or Lubrol WX extraction in MDCK cells in order to understand the differential effect of these detergents on membranes and their selectivity in solubilizing or not proteins. Both Lubrol and Triton DRMs were enriched with cholesterol over the lysate, thus exhibiting characteristics consistent with the properties of membrane rafts. However, the two DRM fractions differed considerably in the ratio between lipids of the inner and outer membrane leaflets. Lubrol DRMs were especially enriched with phosphatidylethanolamine, including polyunsaturated species with long fatty acyl chains. Lubrol and Triton DRMs also differed in the amount of raft transmembrane proteins and raft proteins anchored to the cytoplasmic leaflet. Our results suggest that the inner side of rafts is enriched with phosphatidylethanolamine and cholesterol, and is more solubilized by Triton X-100 than by Lubrol WX.

Electrochemical Corrosion Properties of Commercial Ultra-Thin Copper Foils

NASA Astrophysics Data System (ADS)

Yen, Ming-Hsuan; Liu, Jen-Hsiang; Song, Jenn-Ming; Lin, Shih-Ching

2017-08-01

Ultra-thin electrodeposited Cu foils have been developed for substrate thinning for mobile devices. Considering the corrosion by residual etchants from the lithography process for high-density circuit wiring, this study investigates the microstructural features of ultra-thin electrodeposited Cu foils with a thickness of 3 μm and their electrochemical corrosion performance in CuCl2-based etching solution. X-ray diffraction and electron backscatter diffraction analyses verify that ultra-thin Cu foils exhibit a random texture and equi-axed grains. Polarization curves show that ultra-thin foils exhibit a higher corrosion potential and a lower corrosion current density compared with conventional (220)-oriented foils with fan-like distributed fine-elongated columnar grains. Chronoamperometric results also suggest that ultra-thin foils possess superior corrosion resistance. The passive layer, mainly composed of CuCl and Cu2O, forms and dissolves in sequence during polarization.

Method and apparatus for coating thin foil with a boron coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacy, Jeffrey L.

An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to amore » thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.« less

Two High-Temperature Foil Journal Bearings

NASA Technical Reports Server (NTRS)

Zak, Michail

2006-01-01

An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

Hypolipidemic action of chrysin on Triton WR-1339-induced hyperlipidemia in female C57BL/6 mice.

PubMed

Zarzecki, Micheli Stéfani; Araujo, Stífani M; Bortolotto, Vandreza C; de Paula, Mariane Trindade; Jesse, Cristiano Ricardo; Prigol, Marina

2014-01-01

Chrysin (5,7-dihydroxyflavone) is a flavonoid, natural component of traditional medicinal herbs, present in honey, propolis and many plant extracts. The objective of this study was to investigate the hypolipidemic properties of chrysin on Triton WR-1339-induced hyperlipidemia in female C57BL/6 mice. Triton WR-1339 was administered intraperitoneally (400 mg/kg) to overnight-fasted mice to develop acute hyperlipidemia. Chrysin was administered orally (10 mg/kg) 30 min before Triton WR-1339. At 24 h after Triton WR-1339 injection, blood samples were collected to measure plasma lipid levels. The hepatic thiobarbituric acid reactive substances (TBARS), carbonyl content, non-protein sulfhydryl (NPSH) and ascorbic acid (AA) levels, as well as catalase (CAT) and superoxide dismutase (SOD) activity were recorded. Chrysin administration significantly decreased total cholesterol levels. In addition, it partially decreased non-high density lipoprotein-cholesterol and triglycerides levels in plasma of hyperlipidaemic mice. In addition chrysin administration prevented the increase on TBARS levels and prevented the decrease in SOD activity induced by Triton WR-1339. These findings indicated that chrysin was able to decrease plasma lipids concentration and that its antioxidant properties was, at least in part, involved in the hypolipidaemic action of chrysin.

Additional security features for optically variable foils

NASA Astrophysics Data System (ADS)

Marshall, Allan C.; Russo, Frank

1998-04-01

For thousands of years, man has exploited the attraction and radiance of pure gold to adorn articles of great significance. Today, designers decorate packaging with metallic gold foils to maintain the prestige of luxury items such as perfumes, chocolates, wine and whisky, and to add visible appeal and value to wide range of products. However, today's products do not call for the hand beaten gold leaf of the Ancient Egyptians, instead a rapid production technology exists which makes use of accurately coated thin polymer films and vacuum deposited metallic layers. Stamping Foils Technology is highly versatile since several different layers may be combined into one product, each providing a different function. Not only can a foil bring visual appeal to an article, it can provide physical and chemical resistance properties and also protect an article from human forms of interference, such as counterfeiting, copying or tampering. Stamping foils have proved to be a highly effective vehicle for applying optical devices to items requiring this type of protection. Credit cards, bank notes, personal identification documents and more recently high value packaged items such as software and perfumes are protected by optically variable devices applied using stamping foil technology.

Triton burnup in plasma focus plasmas

NASA Astrophysics Data System (ADS)

Brzosko, Jan S.; Brzosko, Jan R., Jr.; Robouch, Benjamin V.; Ingrosso, Luigi

1995-04-01

Pure deuterium plasma discharge from plasma focus breeds 1.01 MeV tritons via the D(d,p)T fusion branch, which has the same cross section as the D(d,n)3He (En=2.45 MeV) fusion branch. Tritons are trapped in and collide with the background deuterium plasma, producing 14.1 MeV neutrons via the D(t,n)4He reaction. The paper presents published in preliminary form as well as unpublished experimental data and theoretical studies of the neutron yield ratio R=Yn(14.1 MeV)/Yn(2.45 MeV). The experimental data were obtained from 1 MJ Frascati plasma focus operated at W=490 kJ with pure deuterium plasma (in the early 1980s). Neutrons were monitored using the nuclear activation method and nuclear emulsions. The present theoretical analysis of the experimental data is based on an exact adaptation of the binary encounter theory developed by Gryzinski. It is found that the experimentally defined value 1ṡ10-3

Role of triton X-100 and hydrothermal treatment on the morphological features of nanoporous hydroxyapatite nanorods.

PubMed

Iyyappan, E; Wilson, P; Sheela, K; Ramya, R

2016-06-01

Hydroxyapatite (HA) particles were synthesized using Ca(NO3)2·4H2O and (NH4)2HPO4 as precursors with varying contents of non-ionic surfactant viz., triton X-100 (organic modifier) via co-precipitation method followed by hydrothermal treatment. The prepared HA particles have been characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Energy Dispersive X-ray Analysis (EDX), High Resolution Scanning Electron Microscopy (HRSEM), High Resolution Transmission Electron Microscopy (HRTEM) and Nitrogen adsorption-desorption experiments. The XRD and FTIR studies indicate the formation of HA phase in all the synthesized samples. The specific roles of triton X-100 and hydrothermal treatment in dispersing and in directing the crystal growth respectively have been discussed by comparing the observations from individual experiments using triton X-100 and hydrothermal treatment with that of combined protocol involving both. The plausible mechanism for the individual roles of both triton X-100 and hydrothermal treatment have been proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

Developing NanoFoil-Heated Thin-Film Thermal Battery

DTIC Science & Technology

2013-09-01

buffer discs (in gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat...of the fuse strip with a Microtherm disc. Cathode Electrolyte Anode Microtherm Heat paper NanoFoil Buffer Agilent 34970A 606.5 Nichrome wire Maccor...gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat loss

Birefringence and dichroism of poly(vinyl-alcohol) foils containing phthalazinium ylids

NASA Astrophysics Data System (ADS)

Rogojanu, Alina; Dascalu, Carmen Felicia; Zelinschi, Beatrice Carmen; Caprosu, Maria; Dorohoi, Dana Ortansa

2011-10-01

Pure and colored with phthalazinium ylids poly(vinyl-alcohol) (PVA) foils were stretched under gentile heating. The birefringence of the thin foils was determined with a Babinet compensator standardized for yellow radiation of a Sodium lamp. The determined birefringence of the colored PVA foils is higher than that of the pure PVA foils. This fact indicates that the phthalazinium ylids facilitate the increase in the anisotropy of the stretched foils. The visible absorption electronic band of phthalazinium ylids was used to estimate the dichroic ratio and the degree of order of the ylid molecules in the stretched PVA foils. An increase in dichroism and birefringence with the degree of stretching has been evidenced for uncolored and colored PVA foils.

Characterization of Graphene Stripper Foils in 11-MeV Cyclotrons

NASA Astrophysics Data System (ADS)

Korenev, Sergey; Dishman, Rick; Yebra, Alberto; Meshcheryakov, Nikolay; Smirnov, Ilya; Pavlovsky, Igor; Fink, Richard

An experimental study of the use of graphene as an extractor (stripper) foil in the 11-MeV Siemens Eclipse Cyclotron is discussed in this paper. The main advantage of graphene is its high thermal conductivity compared to that of amorphous carbon films. Graphene also has significant mechanical strength. The lifetime of the graphene foils under proton bombardment exceeded 16,000 μAh. Graphene-based stripper foils demonstrated a significant increase in the transmission factor (defined as the ratio of the beam current on the target to the beam current on the stripper foil), which was approximately 90%. Fabrication of the graphene-based foils is discussed. The pros and cons of using the graphene material as a stripper foil in cyclotrons are analyzed.

SNS STRIPPER FOIL FAILURE MODES AND THEIR CURES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galambos, John D; Luck, Chris; Plum, Michael A

2010-01-01

The diamond stripper foils in use at the Spallation Neutron Source worked successfully with no failures until May 3, 2009, when we started experiencing a rash of foil system failures after increasing the beam power to ~840 kW. The main contributors to the failures are thought to be 1) convoy electrons, stripped from the incoming H beam, that strike the foil bracket and may also reflect back from the electron catcher, and 2) vacuum breakdown from the charge developed on the foil by secondary electron emission. In this paper we will detail these and other failure mechanisms, and describe themore » improvements we have made to mitigate them.« less

Hot foil transducer skin friction sensor

NASA Technical Reports Server (NTRS)

Vranas, T. (Inventor)

1982-01-01

The device utilizes foil transducers with only one edge exposed to the fluid flow. The surfaces are polished producing a foil transducer that does not generate turbulence while sufficiently thick to carry the required electrical current for high temperature fluid flow. The assembly utilizes a precut layered metal sandwich with attached electrodes eliminating a need for welding and individual sensor calibration.

Performance of Simple Gas Foil Thrust Bearings in Air

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.

2012-01-01

Foil bearings are self-acting hydrodynamics devices used to support high speed rotating machinery. The advantages that they offer to process fluid lubricated machines include: high rotational speed capability, no auxiliary lubrication system, non-contacting high speed operation, and improved damping as compared to rigid hydrodynamic bearings. NASA has had a sporadic research program in this technology for almost 6 decades. Advances in the technology and understanding of foil journal bearings have enabled several new commercial products in recent years. These products include oil-free turbochargers for both heavy trucks and automobiles, high speed electric motors, microturbines for distributed power generation, and turbojet engines. However, the foil thrust bearing has not received a complimentary level of research and therefore has become the weak link of oil-free turbomachinery. In an effort to both provide machine designers with basic performance parameters and to elucidate the underlying physics of foil thrust bearings, NASA Glenn Research Center has completed an effort to experimentally measure the performance of simple gas foil thrust bearing in air. The database includes simple bump foil supported thrust bearings with full geometry and manufacturing techniques available to the user. Test conditions consist of air at ambient pressure and temperatures up to 500 C and rotational speeds to 55,000 rpm. A complete set of axial load, frictional torque, and rotational speed is presented for two different compliant sub-structures and inter-pad gaps. Data obtained from commercially available foil thrust bearings both with and without active cooling is presented for comparison. A significant observation made possible by this data set is the speed-load capacity characteristic of foil thrust bearings. Whereas for the foil journal bearing the load capacity increases linearly with rotational speed, the foil thrust bearing operates in the hydrodynamic high speed limit. In

Astrometry of Single-Chord Occultations: Application to the 1993 Triton Event

NASA Technical Reports Server (NTRS)

Olkin, Catherine B.; Elliot, J. L.; Bus, Schelte J.; McDonald, Stephen W.; Dahn, Conrad C.

1996-01-01

This paper outlines a method for reducing astrometric data to derive the closest approach time and distance to the center of an occultation shadow for a single observer. The method applies to CCD frames, strip scans or photographic plates and uses a set of field stars of unknown positions to define a common coordinate system for all frames. The motion of the occulting body is used to establish the transformation between this common coordinate system and the celestial coordinate system of the body's ephemeris. This method is demonstrated by application to the Tr6O occultation by Triton on 1993 July 10 UT. Over an interval of four nights that included the occultation time, 80 frames of Triton and Tr6O were taken near the meridian with the U.S. Naval Observatory (USNO) 61-inch astrometric reflector. Application of the method presented here to these data yields a closest approach distance of 359 +/- 133 km (corresponding to 0.017 +/- 0.006 arcsec) for the occultation chord obtained with the Kuiper Airborne Observatory (KAO). Comparison of the astrometric closest approach time with the KAO light-curve midtime shows a difference of 2.2 +/- 4.1 s. Relative photometry of Triton and Tr6O, needed for photometric calibration of the occultation light curve, is also presented.

Coherent synchrotron emission in transmission with double foil target

NASA Astrophysics Data System (ADS)

Xu, X. R.; Qiao, B.; Chang, H. X.; Zhang, Y. X.; Zhang, H.; Zhong, C. L.; Zhou, C. T.; Zhu, S. P.; He, X. T.

2018-04-01

Generation of intense single attosecond pulses from coherent synchrotron emission (CSE), in the transmitted direction of the laser-irradiated double foil targets, has been investigated theoretically and numerically. Unlike conventional CSE in the single foil target case, here the dense electron nanobunch is formed in the vacuum gap between two foils, which is composed of the electrons blown out from the first ultrathin foil. Owing to the existence of the vacuum gap, the electron nanobunch can be accelerated to more energy. In addition, more laser energy can penetrate through the nanobunch and get reflected from the second foil. These reflected lasers and electron nanobunches interact with each other and results in enhanced CSE and consequently, the generation of intense attosecond pulses. Particle-in-cell simulations show that a single attosecond pulse with duration of 18 {as}, photon energy > 0.16 {keV} and peak intensity of 1.7× {10}20 {{W}}/{cm}}2 can be obtained from the double-foil targets irradiated by a laser at intensity of 7.7× {10}21 {{W}}/{cm}}2.

Theoretical performance of foil journal bearings

NASA Technical Reports Server (NTRS)

Carpino, M.; Peng, J.-P.

1991-01-01

A modified forward iteration approach for the coupled solution of foil bearings is presented. The method is used to predict the steady state theoretical performance of a journal type gas bearing constructed from an inextensible shell supported by an elastic foundation. Bending effects are treated as negligible. Finite element methods are used to predict both the foil deflections and the pressure distribution in the gas film.

Pulsed electric discharge laser technology. Electron beam window foil material

NASA Astrophysics Data System (ADS)

McGeoch, M. W.; Defuria, A. J.; Pike, C. T.

1984-01-01

An experimental and theoretical study of titanium alloy foil windows is described. The alloys considered are Ti 15-3-3-3, Ti 3-2.5, and CP Ti(4). The foil thickness ranges from 0.5 mil to 1.0 mil. Tensile strength data is presented for 75 F and 600 F. High-cycle (10 to the 7th power) fatigue data is presented to Ti 15-3-3-3 and Ti 3-2.5 at 75 F and 600 F. Crystal structures are shown for all the alloys. Measurements of the biaxial, or membrane, strength of the alloys is presented. A simulation of laser pulsed overpressure conditions is described, and the foil fatigue under these conditions is documented. The stresses in pressure loaded foil windows were calculated by the finite element method, both for static and dynamic loading. The shape of the foil support rib was optimized to minimize the foil stresses. A correlation was performed between the computed stress cycling under pulsed loading and the measured fatigue strength in uniaxial tension. As a check on the pulse simulation, the actual movement of an electron-beam foil window was measured by interferometry. A speckle interferometer which allows measurement of the movement of unpolished foil surfaces is described.

Roles of size and kinematics in drag reduction for two tandem flexible foils

NASA Astrophysics Data System (ADS)

Chao, Li-Ming; Zhang, Dong; Pan, Guang

2017-11-01

The effect of size and kinematics difference between two tandem flexible foils on drag reduction have been numerically studied. Compared with single foil, it is found that the kinematics difference between two foils would not play a significant role in reducing drag, while the size difference between two foils significantly affects the drag reduction in this two foil system. For leading foil, it always enjoys drag reduction and the highest drag reduction can be observed at bigger size difference and gap distance between two foil as 22%. For trailing foil, it suffers drag increase when the gap distance between two foils is smaller, while it enjoys drag decrease when the size difference between two foils is bigger enough. The hydrodynamic interaction between such actively undulated foils also has been uncovered and used to explain the mechanisms of drag reduction.

Triton, Pluto, and Titan: A Comparison of Haze Photometry

NASA Astrophysics Data System (ADS)

Buratti, Bonnie J.; Hillier, John K.; Abgarian, Mary; Kutsop, Nicholas; Devins, Spencer; Mosher, Joel A.; Stern, S. Alan; Weaver, Harold A.; Olkin, Catherine; Young, Leslie; Ennico, Kimberly; New Horizons Science Team

2017-10-01

As Kuiper Belt Objects of similar size and albedo, Triton and Pluto were thought to be kindred bodies exhibiting like geologic histories and features, with possible seasonal volatile transport in their polar regions. During the flyby of Pluto in July 2015, active geological processes were observed on the planet (Stern et al., 2015), and a substantial haze layer that was more akin to Titan’s was observed (Gladstone et. al., 2016). Multiple haze layers were discovered surrounding the dwarf planet (Cheng et al. 2017).Using a radiative transfer model based on Chandrasekhar’s “Planetary Problem” of an optically thin atmosphere and a surface of arbitrary single scattering albedo and single particle phase function (Chandrasekhar, 1960; Hillier et al., 1990, 1991; Buratti et al., 2011), we have characterized the optical depth and surface properties of Pluto, Triton, and Titan. The forward-scattering properties of the haze can also be quantified by this model. Optical imaging data was analyzed for Triton and Pluto. For Titan we made use of published data on Titan (Tomasko and West, 2009) plus new Cassini Visual Infrared Mapping Spectrometer (VIMS) data, which spans the wavelength range between 0.35 and 5.2 microns, and which has several channels in the mid-infrared where both the haze opacity is relatively low and the atmosphere is optically thin. Pluto’s atmosphere is more optically thick than Triton’s but both are far thinner than Titan’s. The composition of Triton’s haze layer differs markedly from Titan’s. Observations of Pluto’s haze reveal a bluish color (Gladstone et al., 2016), but the reddish tint of possible haze deposits on the surface (Stern et al., 2015; Buratti et al., 2015) suggest Pluto’s haze composition is Titan-like. Institute of Technology. Government sponsorship acknowledged.

Nonlinear dynamic analysis of rigid rotor supported by gas foil bearings: Effects of gas film and foil structure on subsynchronous vibrations

NASA Astrophysics Data System (ADS)

Guo, Zhiyang; Feng, Kai; Liu, Tianyu; Lyu, Peng; Zhang, Tao

2018-07-01

Highly nonlinear subsynchronous vibrations are the main causing factors of failure in gas foil bearing (GFB)-rotor systems. Thus, investigating the vibration generation mechanisms and the relationship between subsynchronous vibrations and GFBs is necessary to ensure the healthy operation of rotor systems. In this study, an integrated nonlinear dynamic model with the consideration of shaft motion, unsteady gas film, and deformations of foil structure is established to investigate the effect of gas film and foil structure on system subsynchronous response. One test rig of GFB-rotor system is developed for model comparison. High agreement is shown between the prediction and test data, especially in the frequency domain. The nonlinear dynamic response is analyzed using waterfall plots, operation deflection shapes, journal orbits, Poincaré maps, and fast Fourier transforms. The parameter studies reveal that subsynchronous vibrations are highly related to gas film and foil structure. Subsynchronous vibrations can be adjusted by parameters such as bump stiffness, nominal clearance, and static loads. Therefore, gas foil bearing parameters should be carefully adjusted by system manufacturers to achieve the best rotordynamic performance.

Method of fabricating a uranium-bearing foil

DOEpatents

Gooch, Jackie G [Seymour, TN; DeMint, Amy L [Kingston, TN

2012-04-24

Methods of fabricating a uranium-bearing foil are described. The foil may be substantially pure uranium, or may be a uranium alloy such as a uranium-molybdenum alloy. The method typically includes a series of hot rolling operations on a cast plate material to form a thin sheet. These hot rolling operations are typically performed using a process where each pass reduces the thickness of the plate by a substantially constant percentage. The sheet is typically then annealed and then cooled. The process typically concludes with a series of cold rolling passes where each pass reduces the thickness of the plate by a substantially constant thickness amount to form the foil.

Gas electron multiplier (GEM) foil test, repair and effective gain calculation

NASA Astrophysics Data System (ADS)

Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

2018-06-01

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

Photometric Monitoring of Triton at Sommers-Bausch Observatory in 2000

NASA Technical Reports Server (NTRS)

Young, L. A.; Bullock, M. A.; Colwell, W. B.; Durda, D. D.; Gleason, K.; Parker, J. W.; Stern, S. A.; Terrell, D.; Young, E. F.

2001-01-01

We undertook pilot program to develop an observing and analysis strategy that can be used to measure Triton's B and V albedos with 0.05 magnitude accuracy at moderate-to-small telescopes, under moderate-to-poor seeing conditions. Additional information is contained in the original extended abstract.

Anomalous behavior of poly(ethylene glycol) p-tert-octylphenyl ether (Triton X-100) in the water-cyclohexane system

NASA Astrophysics Data System (ADS)

Chernysheva, M. G.; Tyasto, Z. A.; Badun, G. A.

2009-02-01

The distribution of Triton X-100 nonionic surfactant in the water-cyclohexane system was investigated by the scintillating phase method. It was shown that an increase in the distribution coefficient as the volume ratio between the aqueous and organic phases grew was explained by the presence in Triton X-100 of homologues with different numbers of ethoxyethyl groups and with the distribution coefficients between the phases different by many times. For the real composition of Triton X-100, distribution coefficients of components of the surfactant were estimated, and the behavior of the surfactant in the system under consideration was simulated; the results were in close agreement with the experimental data.

Induction Bonding of Prepreg Tape and Titanium Foil

NASA Technical Reports Server (NTRS)

Messier, Bernadette C.; Hinkley, Jeffrey A.; Johnston, Norman J.

1998-01-01

Hybrid structural laminates made of titanium foil and carbon fiber reinforced polymer composite offer a potential for improved performance in aircraft structural applications. To obtain information needed for the automated fabrication of hybrid laminates, a series of bench scale tests were conducted of the magnetic induction bonding of titanium foil and thermoplastic prepreg tape. Foil and prepreg specimens were placed in the gap of a toroid magnet mounted in a bench press. Several magnet power supplies were used to study power at levels from 0.5 to 1.75 kW and frequencies from 50 to 120 kHz. Sol-gel surface-treated titanium foil, 0.0125 cm thick, and PIXA/IM7 prepreg tape were used in several lay-up configurations. Data were obtained on wedge peel bond strength, heating rate, and temperature ramp over a range of magnet power levels and frequencies at different "power-on" times for several magnet gap dimensions. These data will be utilized in assessing the potential for automated processing. Peel strengths of foil-tape bonds depended on the maximum temperature reached during heating and on the applied pressure. Maximum peel strengths were achieved at 1.25kW and 8OkHz. Induction heating of the foil appears to be capable of good bonding up to 10 plies of tape. Heat transfer calculations indicate that a 20-40 C temperature difference exists across the tape thickness during heat-up.

Insulating effectiveness of self-spacing dimpled foil

NASA Technical Reports Server (NTRS)

Bond, J. A.

1972-01-01

Experimental data are graphed for determining conductive heat losses of multilayer insulation as function of number of foil layers. Foil was 0.0051 cm thick Nb, 1% Zr refractory alloy, dimpled to 0.0254 cm with approximately 28 dimples/sq cm. Heat losses were determined at 0.1 microtorr between 700 and 1089 K.

[Effects of Triton X-100 on the oxygen uptake rate of photosystem I particles treated at 70 degrees C].

PubMed

Chen, Wei; Yang, Zhen-Le; Li, Liang-Bi; Kuang, Ting-Yun

2005-06-01

The characteristics including oxygen uptake rates, fluorescence spectra and absorption spectra of photosystem I particles with or without Triton-X 100 treatment before or after the incubation at 70 degrees C for 10 min were compared. The oxygen uptake rates of photosystem I particles decreased after being incubated at 70 degrees C for 10 min, which could be recovered by the addition of Triton-X 100. Singlet oxygen was formed when the light-harvesting complex I was separated from the core complex of photosystem I, which resulted in high oxygen uptake rate. There was much difference in the fluorescence spectra of photosystem I particles between photosystem I particles treated with Triton-X 100 after the incubation at 70 degrees C for 10 min or not, which implies the ability of Triton-X 100 to promote the recovery of photosystem I particles after the incubation at 70 degrees C for 10 min.

Method for laser welding ultra-thin metal foils

DOEpatents

Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

1996-03-26

A method for simultaneously cutting and welding ultra-thin foils having a thickness of less than 0.002 inches wherein two ultra-thin films are stacked and clamped together. A pulsed laser such as of the Neodymium: YAG type is provided and the beam of the laser is directed onto the stacked films to cut a channel through the films. The laser is moved relative to the stacked foils to cut the stacked foils at successive locations and to form a plurality of connected weld beads to form a continuous weld. 5 figs.

Method for laser welding ultra-thin metal foils

DOEpatents

Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

1996-01-01

A method for simultaneously cutting and welding ultra-thin foils having a thickness of less than 0.002 inches wherein two ultra-thin films are stacked and clamped together. A pulsed laser such as of the Neodymium: YAG type is provided and the beam of the laser is directed onto the stacked films to cut a channel through the films. The laser is moved relative to the stacked foils to cut the stacked foils at successive locations and to form a plurality of connected weld beads to form a continuous weld.

Elevated-Temperature Tensile-Testing of Foil-Gage Metals

NASA Technical Reports Server (NTRS)

Blackburn, L. B.; Ellingsworth, J. R.

1986-01-01

Automated system for measuring strain in metal foils at temperatures above 500 degrees F (260 degrees C) uses mechanical extensometer and displacement transducer. System includes counterbalance feature, which eliminates weight contribution of extensometer and reduces grip pressure required for attachment to specimen. Counterbalancing feature overcomes two major difficulties in using extensometers with foil-gage specimens: (1) Weight of extensometer and transducer represents significant fraction of total load applied to specimen and may actually damage it; and (2) grip pressure required for attachment of extensometer to specimens may induce bending stresses in foil-gage materials.

An experimental and theoretical study of structural damping in compliant foil bearings

NASA Technical Reports Server (NTRS)

Ku, C.-P. Roger

1994-01-01

This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil bearings. This study provided and opportunity to quantify the structural damping of bump foil strips. The experimental data were compared to results obtained by a theoretical model developed earlier. The effects of bearing design parameters, such as static loads, dynamic displacement amplitudes, bump configurations, pivot locations, surface coatings, and lubricant were also evaluated. An understanding of the dynamic characteristics of bump foil strips resulting from this work offers designers a means for enhancing the design of high-performance compliant foil bearings.

A suspended boron foil multi-wire proportional counter neutron detector

NASA Astrophysics Data System (ADS)

Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

2014-12-01

Three natural boron foils, approximately 1.0 cm in diameter and 1.0 μm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the 10B(n,α)7Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal-neutron detection efficiency for enriched 10B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

Effect of Circuit Inductance on Ceramics Joining by Titanium Foil Explosion

NASA Astrophysics Data System (ADS)

Takada, Yoshihiro; Takaki, Koichi; Itagaki, Minoru; Mukaigawa, Seiji; Fujiwara, Tamiya; Ohshima, Shuzo; Takahashi, Ikuo; Kuwashima, Takayuki

This article describes the influences of circuit inductance on alumina (Al2O3) tile joining using explosive titanium foil. Several kAs pulse current was supplied from 8.28 µF storage capacitor to the 50 µm thickness titanium foil which was sandwiched between the Al2O3 tiles with pressure of 8.3 MPa. The temperature of the foil was rapidly increased owing to ohmic heating with the large current, and then the foil was liquefied and vaporized. The Al2O3 tiles were successfully bonded when the input energy to the titanium foil was higher than the energy required for the foil vaporization. The bonding strength increases with increasing the energy input to the foil. However, the foil explosion cracked the tiles when the input energy exceeds a critical value. Increasing the circuit inductance from 1.13 µH to 64.8 µH, the critical energy of tile cracking increase from 160 J to 507 J, respectively. the maximum bonding strength of 330 kg was obtained when the circuit inductance was 21.8 µH. An investigation of the interfacial structure of the joints using electron probe micro-analysis revealed that distinct reaction areas existed in the interlayer.

Development, characterization and qualification of first GEM foils produced in India

NASA Astrophysics Data System (ADS)

Shah, Aashaq; Ahmed, Asar; Gola, Mohit; Sharma, Ram Krishna; Malhotra, Shivali; Kumar, Ashok; Naimuddin, Md.; Menon, Pradeep; Srinivasan, K.

2018-06-01

The increasing demand for Gas Electron Multiplier (GEM) foils has been driven by their application in many current and proposed high-energy physics experiments. Micropack, a Bengaluru-based company, has established and commercialized GEM foils for the first time in India. Micropack used the double-mask etching technique to successfully produce 10 cm × 10 cm GEM foil. In this paper, we report on the development as well as the geometrical and electrical properties of these foils, including the size uniformity of the holes and leakage current measurements. Our characterization studies show that the foils are of good quality and satisfy all the necessary quality control criteria.

Positron annihilation lifetime spectroscopy study of Kapton thin foils

NASA Astrophysics Data System (ADS)

Kanda, G. S.; Ravelli, L.; Löwe, B.; Egger, W.; Keeble, D. J.

2016-01-01

Variable energy positron annihilation lifetime spectroscopy (VE-PALS) experiments on polyimide material Kapton are reported. Thin Kapton foils are widely used in a variety of mechanical, electronic applications. PALS provides a sensitive probe of vacancy-related defects in a wide range of materials, including open volume in polymers. Varying the positron implantation energy enables direct measurement of thin foils. Thin Kapton foils are also commonly used to enclose the positron source material in conventional PALS measurements performed with unmoderated radionuclide sources. The results of depth-profiled positron lifetime measurements on 7.6 μm and 25 μm Kapton foils are reported and determine a dominant 385(1) ps lifetime component. The absence of significant nanosecond lifetime component due to positronium formation is confirmed.

Welding bulk metallic glass using nanostructured reactive multilayer foils

NASA Astrophysics Data System (ADS)

Trenkle, Jonathan C.

We have used Al/Ni reactive foils to weld Zr57Ti 5Cu20Ni8Al10 metallic glasses. The welds are a composite morphology comprised of glass ligaments and intermetallic AlNi (the product of the reactive foil). The presence of the presumably brittle intermetallic (in lieu of the glass) is expected to limit the mechanical properties of the welds. Based on fracture toughness measurements and the crack propagation paths, we conclude that virtually all of the toughness can be ascribed to the presence of the metallic glass ligaments. Increasing the pressure applied during welding increases the fraction of the joint made of these ligaments and so increases the fracture toughness as well. To eliminate the intermetallic from the weld altogether, we attempted to fabricate reactive mulitlayer foils that form an amorphous product by melting and cooling rapidly during a self-propagating reaction. We began with reactive foils with overall composition Zr2Ni but quickly determined that the foils did not fully melt. We then attempted to lower the melting temperature and increase the glass forming ability and the heat of mixing by adding Al and Cu. These foils again did not fully melt. Finally we systematically determined that foils of overall compositions Hf37Ni63, Ni 80P20, and Ni60P40, which are all known binary metallic glasses, will potentially melt during a self-propagating reaction. Knowledge of the phase transformations during a self-propagating reaction is necessary to engineer reactive foils for future applications. Furthermore, reactive foils provide an opportunity to study phase transformations under high heating rates not easily achievable. Characterizing the processes in the reaction zone however is challenging, requiring both temporal resolution better than ˜ 100 mus (the time required for the reaction front to pass a fixed location) and spatial resolution of < 100 mum (the approximate width of the reaction zone). Using synchrotron x-ray radiation, we have studied these

Apparatus and process for ultrasonic seam welding stainless steel foils

DOEpatents

Leigh, Richard W.

1992-01-01

An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

Misalignment in Gas Foil Journal Bearings: An Experimental Study

NASA Technical Reports Server (NTRS)

Howard, Samuel A.

2008-01-01

As gas foil journal bearings become more prevalent in production machines, such as small gas turbine propulsion systems and microturbines, system-level performance issues must be identified and quantified in order to provide for successful design practices. Several examples of system-level design parameters that are not fully understood in foil bearing systems are thermal management schemes, alignment requirements, balance requirements, thrust load balancing, and others. In order to address some of these deficiencies and begin to develop guidelines, this paper presents a preliminary experimental investigation of the misalignment tolerance of gas foil journal bearing systems. Using a notional gas foil bearing supported rotor and a laser-based shaft alignment system, increasing levels of misalignment are imparted to the bearing supports while monitoring temperature at the bearing edges. The amount of misalignment that induces bearing failure is identified and compared to other conventional bearing types such as cylindrical roller bearings and angular contact ball bearings. Additionally, the dynamic response of the rotor indicates that the gas foil bearing force coefficients may be affected by misalignment.

200 kj copper foil fuses. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McClenahan, C.R.; Goforth, J.H.; Degnan, J.H.

1980-04-01

A 200-kJ, 50-kV capacitor bank has been discharged into 1-mil-thick copper foils immersed in fine glass beads. These foils ranged in length from 27 to 71 cm and in width from 15 to 40 cm. Voltage spikes of over 250 kV were produced by the resulting fuse behavior of the foil. Moreover, the current turned off at a rate that was over 6 times the initial bank dI/dt. Full widths at half maxima for the voltage and dI/dt spikes were about 0.5 microsec, with some as short as 300 nanosec. Electrical breakdown was prevented in all but one size fuzemore » with maximum applied fields of 7 kV/cm. Fuses that were split into two parallel sections have been tested, and the effects relative to one-piece fuses are much larger than would be expected on the basis of inductance differences alone. A resistivity model for copper foil fuses, which differs from previous work in that it includes a current density dependence, has been devised. Fuse behavior is predicted with reasonable accuracy over a wide range of foil sizes by a quasi-two-dimensional fuse code that incorporates this resistivity model. A variation of Maisonnier's method for predicting optimum fuze size has been derived. This method is valid if the risetime of the bank exceeds 3 microsec, in which case it can be expected to be applicable over a wide range of peak current densities.« less

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacheco, Robin Montoya; Alexander, David John; Mccabe, Rodney James

2017-01-20

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Almore » cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.« less

Method of high-density foil fabrication

DOEpatents

Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.

2003-12-16

A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

Process for producing molybdenum foil and collapsible tubing

NASA Technical Reports Server (NTRS)

Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

1971-01-01

Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

Simultaneous laser cutting and welding of metal foil to edge of a plate

DOEpatents

Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

1996-01-01

A method of welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads.

Simultaneous laser cutting and welding of metal foil to edge of a plate

DOEpatents

Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

1996-03-19

A method is described for welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads. 7 figs.

Measurements of laser generated soft X-ray emission from irradiated gold foils

DOE PAGES

Davis, J. S.; Frank, Y.; Raicher, E.; ...

2016-08-22

We measured soft x-ray emission from laser irradiated gold foils at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

Measurements of laser generated soft X-ray emission from irradiated gold foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, J. S.; Keiter, P. A.; Klein, S. R.

Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

Measurements of laser generated soft X-ray emission from irradiated gold foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, J. S.; Frank, Y.; Raicher, E.

We measured soft x-ray emission from laser irradiated gold foils at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

A novel carbon coating technique for foil bolometers

NASA Astrophysics Data System (ADS)

Sheikh, U. A.; Duval, B. P.; Labit, B.; Nespoli, F.

2016-11-01

Naked foil bolometers can reflect a significant fraction of incident energy and therefore cannot be used for absolute measurements. This paper outlines a novel coating approach to address this problem by blackening the surface of gold foil bolometers using physical vapour deposition. An experimental bolometer was built containing four standard gold foil bolometers, of which two were coated with 100+ nm of carbon. All bolometers were collimated and observed the same relatively high temperature, ohmically heated plasma. Preliminary results showed 13%-15% more incident power was measured by the coated bolometers and this is expected to be much higher in future TCV detached divertor experiments.

The Triton: Design concepts and methods

NASA Technical Reports Server (NTRS)

Meholic, Greg; Singer, Michael; Vanryn, Percy; Brown, Rhonda; Tella, Gustavo; Harvey, Bob

1992-01-01

During the design of the C & P Aerospace Triton, a few problems were encountered that necessitated changes in the configuration. After the initial concept phase, the aspect ratio was increased from 7 to 7.6 to produce a greater lift to drag ratio (L/D = 13) which satisfied the horsepower requirements (118 hp using the Lycoming O-235 engine). The initial concept had a wing planform area of 134 sq. ft. Detailed wing sizing analysis enlarged the planform area to 150 sq. ft., without changing its layout or location. The most significant changes, however, were made just prior to inboard profile design. The fuselage external diameter was reduced from 54 to 50 inches to reduce drag to meet the desired cruise speed of 120 knots. Also, the nose was extended 6 inches to accommodate landing gear placement. Without the extension, the nosewheel received an unacceptable percentage (25 percent) of the landing weight. The final change in the configuration was made in accordance with the stability and control analysis. In order to reduce the static margin from 20 to 13 percent, the horizontal tail area was reduced from 32.02 to 25.0 sq. ft. The Triton meets all the specifications set forth in the design criteria. If time permitted another iteration of the calculations, two significant changes would be made. The vertical stabilizer area would be reduced to decrease the aircraft lateral stability slope since the current value was too high in relation to the directional stability slope. Also, the aileron size would be decreased to reduce the roll rate below the current 106 deg/second. Doing so would allow greater flap area (increasing CL(sub max)) and thus reduce the overall wing area. C & P would also recalculate the horsepower and drag values to further validate the 120 knot cruising speed.

Tubular hydrogen permeable metal foil membrane and method of fabrication

DOEpatents

Paglieri, Stephen N.; Birdsell, Stephen A.; Barbero, Robert S.; Snow, Ronny C.; Smith, Frank M.

2006-04-04

A tubular hydrogen permeable metal membrane and fabrication process comprises obtaining a metal alloy foil having two surfaces, coating the surfaces with a metal or metal alloy catalytic layer to produce a hydrogen permeable metal membrane, sizing the membrane into a sheet with two long edges, wrapping the membrane around an elongated expandable rod with the two long edges aligned and overlapping to facilitate welding of the two together, placing the foil wrapped rod into a surrounding fixture housing with the two aligned and overlapping foil edges accessible through an elongated aperture in the surrounding fixture housing, expanding the elongated expandable rod within the surrounding fixture housing to tighten the foil about the expanded rod, welding the two long overlapping foil edges to one another generating a tubular membrane, and removing the tubular membrane from within the surrounding fixture housing and the expandable rod from with the tubular membrane.

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tin-coated lead foil capsules for wine bottles... Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one or both sides with a thin layer...

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming.

PubMed

Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

2016-07-13

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Compliant Foil Journal Bearing Performance at Alternate Pressures and Temperatures

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; Puleo, Bernadette J.

2008-01-01

An experimental test program has been conducted to determine the highly loaded performance of current generation gas foil bearings at alternate pressures and temperatures. Typically foil bearing performance has been reported at temperatures relevant to turbomachinery applications but only at an ambient pressure of one atmosphere. This dearth of data at alternate pressures has motivated the current test program. Two facilities were used in the test program, the ambient pressure rig and the high pressure rig. The test program utilized a 35 mm diameter by 27 mm long foil journal bearing having an uncoated Inconel X-750 top foil running against a shaft with a PS304 coated journal. Load capacity tests were conducted at 3, 6, 9, 12, 15, 18, and 21 krpm at temperatures from 25 to 500 C and at pressures from 0.1 to 2.5 atmospheres. Results show an increase in load capacity with increased ambient pressure and a reduction in load capacity with increased ambient temperature. Below one-half atmosphere of ambient pressure a dramatic loss of load capacity is experienced. Additional lightly loaded foil bearing performance in nitrogen at 25 C and up to 48 atmospheres of ambient pressure has also been reported. In the lightly loaded region of operation the power loss increases for increasing pressure at a fixed load. Knowledge of foil bearing performance at operating conditions found within potential machine applications will reduce program development risk of future foil bearing supported turbomachines.

Numerical investigations on aerodynamic forces of deformable foils in hovering motions

NASA Astrophysics Data System (ADS)

Su, Xiaohui; Yin, Zhen; Cao, Yuanwei; Zhao, Yong

2017-04-01

In this paper, the aerodynamic forces of deformable foils for hovering flight are numerically investigated by a two-dimensional finite-volume arbitrary Lagrangian Eulerian Navier-Stokes solver. The effects of deformation on the lift force generation mechanisms of deformable wings in hovering flight are studied by comparison and analysis of deformable and rigid wing results. The prescribed deformation of the wings changes their morphing during hovering motion in both camber and angle of incidence. The effects of deflection amplitude, deflection phase, and rotation location on the aerodynamic performances of the foils, as well as the associated flow structures, are investigated in details, respectively. Results obtained show that foil morphing changes both Leading Edge Vortex (LEV) and Trailing Edge Vortex (TEV) generation and development processes. Consequently, the lift force generation mechanisms of deformable wings differ from those of rigid foil models. For the full deformation foil model studied, the effect of foil deformation enhances its lift force during both wake capture and delayed stall. There is an optimized camber amplitude, which was found to be 0.1*chord among those cases simulated. Partial deformation in the foil does not enhance its lift force due to unfavorable foil camber. TEV is significantly changed by the local angle of attack due to the foil deformation. On the other hand, Trailing Edge Flap (TEF) deflection in the hinge connected two-rigid-plate model directly affects the strength of both the LEV and TEV, thus influencing the entire vortex shedding process. It was found that lift enhancement can reach up to 33.5% just by the TEF deflection alone.

Selecting foils for identification lineups: matching suspects or descriptions?

PubMed

Tunnicliff, J L; Clark, S E

2000-04-01

Two experiments directly compare two methods of selecting foils for identification lineups. The suspect-matched method selects foils based on their match to the suspect, whereas the description-matched method selects foils based on their match to the witness's description of the perpetrator. Theoretical analyses and previous results predict an advantage for description-matched lineups both in terms of correctly identifying the perpetrator and minimizing false identification of innocent suspects. The advantage for description-matched lineups should be particularly pronounced if the foils selected in suspect-matched lineups are too similar to the suspect. In Experiment 1, the lineups were created by trained police officers, and in Experiment 2, the lineups were constructed by undergraduate college students. The results of both experiments showed higher suspect-to-foil similarity for suspect-matched lineups than for description-matched lineups. However, neither experiment showed a difference in correct or false identification rates. Both experiments did, however, show that there may be an advantage for suspect-matched lineups in terms of no-pick and rejection responses. From these results, the endorsement of one method over the other seems premature.

Bi-metal foil gas dynamic bearings with bimorph piezoelectric foils

NASA Astrophysics Data System (ADS)

Sytin, A.; Rodichev, A.; Kulkov, A.

2017-08-01

The present paper considers application of bi-metal materials and coatings to provide necessary strength and wear resistance of the surfaces of rigid and elastic gas dynamic bearings. Authors suggest using multi-layer foils with bimorph piezoelectric elements that operate in the generator regime to determine the deformation of elastic elements, and in the actuator regime to form an optimal shape of the surface of the bearing.

Gas Foil Bearings for Space Propulsion Nuclear Electric Power Generation

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; DellaCorte, Christopher

2006-01-01

The choice of power conversion technology is critical in directing the design of a space vehicle for the future NASA mission to Mars. One candidate design consists of a foil bearing supported turbo alternator driven by a helium-xenon gas mixture heated by a nuclear reactor. The system is a closed-loop, meaning there is a constant volume of process fluid that is sealed from the environment. Therefore, foil bearings are proposed due to their ability to use the process gas as a lubricant. As such, the rotor dynamics of a foil bearing supported rotor is an important factor in the eventual design. The current work describes a rotor dynamic analysis to assess the viability of such a system. A brief technology background, assumptions, analyses, and conclusions are discussed in this report. The results indicate that a foil bearing supported turbo alternator is possible, although more work will be needed to gain knowledge about foil bearing behavior in helium-xenon gas.

Conductive copper sulfide thin films on polyimide foils

NASA Astrophysics Data System (ADS)

Cardoso, J.; Gomez Daza, O.; Ixtlilco, L.; Nair, M. T. S.; Nair, P. K.

2001-02-01

Kapton polyimide is known for its high thermal stability, >400 °C. Copper sulfide thin films of 75 and 100 nm thickness were coated on DuPont Kapton HN polyimide foils of 25 µm thickness by floating them on a chemical bath containing copper complexes and thiourea. The coated foils were annealed at 150-400 °C in nitrogen, converting the coating from CuS to Cu1.8S. The sheet resistance of the annealed coatings (100 nm) is 10-50 Ω/□ and electrical conductivity, 2-10×103 Ω-1 cm- 1, which remain nearly constant even after the foils are immersed in 0.1-1 M HCl for 30-120 min. The coated polyimide has a transmittance (25-35%) peak located in the wavelength region 550-600 nm, with transmittance dropping to near zero below 450 nm and below 10% in the near-infrared spectral region. These characteristics are relevant in solar radiation control applications. The coated foils might also be used as conductive substrates for electrolytic deposition of metals and semiconductors and for optoelectronic device structures.

Dynamic environmental control mechanisms for pneumatic foil constructions

NASA Astrophysics Data System (ADS)

Flor, Jan-Frederik; Wu, Yupeng; Beccarelli, Paolo; Chilton, John

2017-11-01

Membrane and foil structures have become over the last decades an attractive alternative to conventional materials and building systems with increasing implementation in different typologies and scale. The development of transparent, light, flexible and resistant materials like Ethylene Tetrafluoroethylene (ETFE) has triggered a rethinking of the building envelope in the building industry towards lightweight systems. ETFE foil cushions have proven to fulfil the design requirements in terms of structural efficiency and aesthetic values. But the strategies to satisfy increasing demands of energy efficiency and comfort conditions are still under development. The prediction and manipulation of the thermo-optical behaviour of ETFE foil cushion structures currently remain as one of the main challenges for designers and manufacturers. This paper reviews ongoing research regarding the control of the thermo-optical performance of ETFE cushion structures and highlights challenges and possible improvements. An overview of different dynamic and responsive environmental control mechanisms for multilayer foil constructions is provided and the state of the art in building application outlined by the discussion of case studies.

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming

PubMed Central

Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

2016-01-01

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination. PMID:28773692

Development of aerodynamic foil journal bearings for a high speed cryogenic turboexpander

NASA Astrophysics Data System (ADS)

Xiong, L.-Y.; Wu, G.; Hou, Y.; Liu, L.-Q.; Ling, M.-F.; Chen, C.-Z.

The research presented in this paper is aimed at the development of aerodynamic foil journal bearings applying to a small high speed cryogenic turboexpander. A small high speed cryogenic turboexpander is designed. Attention has been paid to the study of the effect of foil stiffness on the vibration performance of bearings. From rotation tests, it is clear that, with the proper choice of foil stiffness, the foil bearing presented here can possess sufficiently high stability. The maximum rotational speed obtained is greater than 230 000 rpm. Therefore, owing to its simplicity and high performance, this type of foil journal bearing can hopefully be applied to a small high speed cryogenic turboexpander.

Quasi-static analysis of foil journal bearings for a Brayton cycle turboalternator

NASA Technical Reports Server (NTRS)

Eshel, A.

1974-01-01

A quasi-static analysis is presented for foil journal bearings designed for a NASA Brayton Cycle Turboalternator. Included in the analysis are effects of 'slack' (due to flexural rigidity of the foil), of frictionally restrained extension of the foil-length in contact with cylindrical guides, of fluid inertia and compressibility, and of thermal expansion of rotor, foil and supporting structure. Comparisons are made with results of early experiments performed by Licht (1968, 1969) and recent data of Licht and Branger (1973). Variatons of film thickness, foil tension and bearing stiffness are presented graphically as functions of pertinent parameters for the case of operation in zero-gravity environment.

Radiation pressure acceleration of corrugated thin foils by Gaussian and super-Gaussian beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adusumilli, K.; Goyal, D.; Tripathi, V. K.

Rayleigh-Taylor instability of radiation pressure accelerated ultrathin foils by laser having Gaussian and super-Gaussian intensity distribution is investigated using a single fluid code. The foil is allowed to have ring shaped surface ripples. The radiation pressure force on such a foil is non-uniform with finite transverse component F{sub r}; F{sub r} varies periodically with r. Subsequently, the ripple grows as the foil moves ahead along z. With a Gaussian beam, the foil acquires an overall curvature due to non-uniformity in radiation pressure and gets thinner. In the process, the ripple perturbation is considerably washed off. With super-Gaussian beam, the ripplemore » is found to be more strongly washed out. In order to avoid transmission of the laser through the thinning foil, a criterion on the foil thickness is obtained.« less

Stratification in Al and Cu foils exploded in vacuum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baksht, R. B.; Electrical Discharge and Plasma Laboratory, Tel Aviv University, Tel Aviv 6997801; Rousskikh, A. G.

2015-10-15

An experiment with exploding foils was carried out at a current density of 0.7 × 10{sup 8} A/cm{sup 2} through the foil with a current density rise rate of about 10{sup 15} A/cm{sup 2} s. To record the strata arising during the foil explosions, a two-frame radiographic system was used that allowed tracing the dynamics of strata formation within one shot. The original striation wavelength was 20–26 μm. It was observed that as the energy deposition to a foil stopped, the striation wavelength increased at a rate of ∼(5–9) × 10{sup 3} cm/s. It is supposed that the most probable reason for the stratification is the thermal instabilitymore » that develops due to an increase in the resistivity of the metal with temperature.« less

Effect of Cerium(III) and ionic liquids on the clouding behavior of Triton X-100 micelles

NASA Astrophysics Data System (ADS)

Sen, Indrani Das; Negi, Charu; Jayaram, Radha V.

2018-04-01

In the present study, the effect of Ce(III) on the clouding behavior of Triton X-100 has been investigated in the presence and absence of imidazolium based ionic liquids of varying chain length and counter ions. Thermodynamic parameters of clouding were calculated to comprehend the underlying interactions between the surfactant and the additives. The cloud point (CP) of Triton X-100 was found to increase with the concentration of Ce(III) and that of the ionic liquids studied. This increase of CP reflects the solubilization of the ionic liquids in the micellar solution1.

Fluid-film foil bearings control engine heat

NASA Astrophysics Data System (ADS)

O'Connor, Leo

1993-05-01

The state-of-the-art of fluid-film foil bearings and their current and prospective applications are briefly reviewed. In particular, attention is given to the general design of fluid-film foil bearings, the materials used, and bearing performance. The applications discussed include launch vehicle turbopumps, turbines used to cool aircraft cabins, and turbocompressors and turboexpanders used in the processing of cryogenic fluids. Future applications may include turbochargers, textile spindles, cryocoolers, motor blowers, heat pumps, and solar chillers.

Further Evidence for Increasing Pressure and a Non-spherical Shape in Triton's Atmosphere

NASA Astrophysics Data System (ADS)

Person, M. J.; Elliot, J. L.; McDonald, S. W.; Buie, M. W.; Dunham, E. W.; Millis, R. L.; Nye, R. A.; Olkin, C. B.; Wasserman, L. H.; Young, L. A.; Hubbard, W. B.; Hill, R.; Reitsema, H. J.; Pasachoff, J. M.; Babcock, B. A.; McConnochie, T. M.; Stone, R. C.

2000-10-01

An occultation by Triton of a star denoted as Tr176 by McDonald & Elliot (AJ 109, 1352), was observed on 1997 July 18 from various locations in Australia and North America. After an extensive prediction effort, two complete chords of the occultation were recorded by our PCCD portable data systems. These chords were combined with three others recorded by another group (Sicardy et al., BAAS 30, 1107) to provide an overall geometric solution for Triton's atmosphere at the occultation pressure. A simple circular fit to these five chords yielded a half-light radius of 1439 +/- 10 km, however least squares fitting revealed a significant deviation from the simple circular projection of a spherical atmosphere. The best fitting ellipse (a first order deviation from the circular solution) yielded a mean radius of 1440 +/- 6 km and an ellipticity of 0.040 +/- 0.003. To further characterize the non-spherical solutions to the geometric fits, methods were developed to analyze the data assuming both circular and elliptical profiles. Circular and elliptically focused light curve models corresponding to the best fitting circular and elliptical geometric solutions were fit to the data. Using these light curve fits, the mean pressure at the 1400 km radius (48 km altitude) derived from all the data was 2.23 +/- 0.28 microbar for the circular model and 2.45 +/- 0.32 microbar for the elliptical model. These pressures agree with those for the Tr180 occultation (which occurred a few months later), so these results are consistent with the conclusions of Elliot et al. (Icarus 143, 425) that Triton's surface pressure has increased from 14.0 microbar at the time of the Voyager encounter to 19.0 microbar in 1997. The mean equivalent-isothermal temperature at 1400 km was 43.6 +/- 3.7 K for the circular model and 42.0 +/- 3.6 K for the elliptical model. Within their calculated errors, the equivalent-isothermal temperatures were the same for all Triton latitudes probed.

Studies of PMMA sintering foils with and without coating by magnetron sputtering Pd

NASA Astrophysics Data System (ADS)

Cutroneo, M.; Mackova, A.; Torrisi, L.; Vad, K.; Csik, A.; Ando', L.; Svecova, B.

2017-09-01

Polymethylmethacrylate thin foils were prepared by using physical and chemical processes aimed at changing certain properties. The density and the optical properties were changed obtaining clear and opaque foils. DC magnetron sputtering method was used to cover the foils with thin metallic palladium layers. The high optical absorbent foils were obtained producing microstructured PMMA microbeads with and without thin metallic coatings. Rutherford Backscattering Spectroscopy, optical investigation and microscopy were employed to characterize the prepared foils useful in the field study of laser-matter interaction.

Method of making porous conductive supports for electrodes. [by electroforming and stacking nickel foils

NASA Technical Reports Server (NTRS)

Schaer, G. R. (Inventor)

1973-01-01

Porous conductive supports for electrochemical cell electrodes are made by electroforming thin corrugated nickel foil, and by stacking pieces of the corrugated foil alternatively with pieces of thin flat nickel foil. Corrugations in successive corrugated pieces are oriented at different angles. Adjacent pieces of foil are bonded by heating in a hydrogen atmosphere and then cutting the stack in planes perpendicular to the foils.

Effects of stern-foil submerged elevation on the lift and drag of a hydrofoil craft

NASA Astrophysics Data System (ADS)

Suastika, K.; Apriansyah

2018-03-01

Effects of the stern-foil submerged elevation on the lift and drag of a hydrofoil craft are studied by using computational fluid dynamics (CFD) and by considering three alternative stern-foil submerged elevations. The submerged elevation of the front foil is kept constant in all the alternatives. From among the alternatives, the deepest stern-foil placement results in the highest stern-foil lift with the highest foil’s lift-to-drag ratio. However, considering the lift-to-drag ratio of the whole foil-strut-hull system, the shallowest stern-foil placement results in the highest lift-to-drag ratio. The struts and the foil’s submerged elevation significantly affects the drag of the whole foil-strut-hull system.

Outdoor Weathering and Dissolution of TNT and Tritonal

DTIC Science & Technology

2009-01-01

ranged from 0.361 to 1.975 g and the Tritonal chunks ran- ged from 2.162 to 5.320 g. Each funnel was attached to a 1-L glass bottle with a #4 rubber ... stopper fitted with two holes, one hole for the funnel stem and the other for a bent copper tube that allows air exchange. The bottles fit snuggly into...dissolved mass averaged about one-third of the total TNT mass loss. This result was surprising because we have had excel- lent HE mass- closure during

Lenz’s law with aluminum foil and a lengthwise slit

NASA Astrophysics Data System (ADS)

Berls, Rob; Ruiz, Michael J.

2018-07-01

The classic demonstration illustrating Lenz’s law by dropping a magnet through a copper pipe is presented using household aluminum foil right out of the box. Then comes the surprise. The teacher presents an aluminum foil cylinder with a missing lengthwise slice (cut before class). Will the demonstration still work? Students are amazed at the result, described in this paper and included in our accompanying video (Ruiz 2018 Video: Lenz’s law with aluminum foil http://mjtruiz.com/ped/aluminum/).

A review of progress and challenges in flapping foil power generation

NASA Astrophysics Data System (ADS)

Young, John; Lai, Joseph C. S.; Platzer, Max F.

2014-05-01

Power may be extracted from a flowing fluid in a variety of ways. Turbines using one or more oscillating foils are under increasingly active investigation, as an alternative to rotary wind turbines and river, oceanic and tidal current water turbines, although industrial development is at a very nascent stage. Such flapping foil turbines promise some key potential advantages, including lower foil velocities (and hence lower noise and wildlife impact), and more effective small-scale and shallow water operation. The role of a number of parameters is investigated, including foil kinematics (modes, frequencies, amplitudes and time histories of motion), foil and system geometry (shape, configuration and structural flexibility), and flow physics effects (Reynolds number and turbulence, shear flows and ground effect). Details of the kinematics are shown to have the single largest influence on power output and efficiency (measured as the ratio of power output to that available and accessible in the fluid stream). The highest levels of power and efficiency are associated with very large foil pitch angles (upwards of 70°) and angles of attack (30-40°), such that the flow is massively separated for much of the flapping cycle, in contrast to rotary turbines which rely on attached flow over as much of the rotor disk as possible. This leads to leading edge vortices comparable in size to the foil chord, and the evolution and interaction of these vortices with the foil as it moves play a central role in determining performance. The other parameters also influence the vortex behaviour, but in general to a lesser degree. Numerous gaps in the research literature and outstanding issues are highlighted.

Foil Bearing Coating Behavior in CO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Matthew; Kruizenga, Alan Michael; Pasch, James Jay

2017-08-01

The Sandia S-CO 2 Recompression Closed Brayton Cycle (RCBC) utilizes a series of gas foil bearings in its turbine-alternator-compressors. At high shaft rotational speed these bearings allow the shaft to ride on a cushion of air. Conversely, during startup and shutdown, the shaft rides along the foil bearing surface. Low-friction coatings are used on bearing surfaces in order to facilitate rotation during these periods. An experimental program was initiated to elucidate the behavior of coated bearing foils in the harsh environments of this system. A test configuration was developed enabling long duration exposure tests, followed by a range of analysesmore » relevant to their performance in a bearing. This report provides a detailed overview of this work. The results contained herein provide valuable information in selecting appropriate coatings for more advanced future bearing-rig tests at the newly established test facility in Sandia-NM.« less

Epitaxial lift-off of electrodeposited single-crystal gold foils for flexible electronics

NASA Astrophysics Data System (ADS)

Mahenderkar, Naveen K.; Chen, Qingzhi; Liu, Ying-Chau; Duchild, Alexander R.; Hofheins, Seth; Chason, Eric; Switzer, Jay A.

2017-03-01

We introduce a simple and inexpensive procedure for epitaxial lift-off of wafer-size flexible and transparent foils of single-crystal gold using silicon as a template. Lateral electrochemical undergrowth of a sacrificial SiOx layer was achieved by photoelectrochemically oxidizing silicon under light irradiation. A 28-nanometer-thick gold foil with a sheet resistance of 7 ohms per square showed only a 4% increase in resistance after 4000 bending cycles. A flexible organic light-emitting diode based on tris(bipyridyl)ruthenium(II) that was spin-coated on a foil exploited the transmittance and flexibility of the gold foil. Cuprous oxide as an inorganic semiconductor that was epitaxially electrodeposited onto the gold foils exhibited a diode quality factor n of 1.6 (where n = 1.0 for an ideal diode), compared with a value of 3.1 for a polycrystalline deposit. Zinc oxide nanowires electrodeposited epitaxially on a gold foil also showed flexibility, with the nanowires intact up to 500 bending cycles.

Development of Gating Foils To Inhibit Ion Feedback Using FPC Production Techniques

NASA Astrophysics Data System (ADS)

Arai, D.; Ikematsu, K.; Sugiyama, A.; Iwamura, M.; Koto, A.; Katsuki, K.; Fujii, K.; Matsuda, T.

2018-02-01

Positive ion feedback from a gas amplification device to the drift region of the Time Projection Chamber for the ILC can deteriorate the position resolution. In order to inhibit the feedback ions, MPGD-based gating foils having good electron transmission have been developed to be used instead of the conventional wire gate. The gating foil needs to control the electric field locally in opening or closing the gate. The gating foil with a GEM (gas electron multiplier)-like structure has larger holes and smaller thickness than standard GEMs for gas amplification. It is known that the foil transmits over 80 % of electrons and blocks ions almost completely. We have developed the gating foils using flexible printed circuit (FPC) production techniques including an improved single-mask process. In this paper, we report on the production technique of 335 μm pitch, 12.5 μm thick gating foil with 80 % transmittance of electrons in ILC conditions.

Monolithic exploding foil initiator

DOEpatents

Welle, Eric J; Vianco, Paul T; Headley, Paul S; Jarrell, Jason A; Garrity, J. Emmett; Shelton, Keegan P; Marley, Stephen K

2012-10-23

A monolithic exploding foil initiator (EFI) or slapper detonator and the method for making the monolithic EFI wherein the exploding bridge and the dielectric from which the flyer will be generated are integrated directly onto the header. In some embodiments, the barrel is directly integrated directly onto the header.

Cutting of Gold Foil in the Genesis Laboratory

NASA Image and Video Library

2005-02-15

The facility for storing and examining Genesis solar wind samples consists of two adjacent laboratories. In these laboratories, the cutting of gold foil to be used in the gathering of the solar wind dust aboard the Genesis spacecraft. Views include: The process of cutting gold foil to be used aboard the Genesis spacecraft. The technicians use Gore-Tex suits with filters as to not contaminate the items.

Magnetic Fano resonances by design in symmetry broken THz meta-foils

PubMed Central

Wu, Jianfeng; Moser, Herbert O.; Li, Rujiang; Yang, Yihao; Jing, Liqiao; Chen, Hongsheng; Breese, Mark B. H.

2017-01-01

Magnetic Fano resonances in there-dimensional symmetry broken meta-foils at THz frequencies are theoretically and experimentally studied. Sharp Fano resonances occur due to the interference between different resonances and can be designed by choosing geometric parameters of the meta-foil. At the Fano resonances, the meta-foil supports antisymmetric modes, whereas, at the main resonance, only a symmetric mode exists. The meta-foil is left-handed at the Fano resonances and shows sharp peaks of the real part of the refractive index in transmission with small effective losses opening a way to very sensitive high-speed sensing of dielectric changes in the surrounding media and of mechanical configuration. PMID:28150797

Origin and Evolution of Nitrogen on Titan, Enceladus, Triton, and Pluto

NASA Technical Reports Server (NTRS)

Atreya, S. K.; Niemann, H. B.; Mahaffy, P. R.; Owen, T. C.

2007-01-01

Nitrogen, together with carbon, hydrogen, oxygen, phosphorus and sulfur (CHNOPS), plays a central role in life as we know it. Indeed, molecular nitrogen is the most abundant component of the terrestrial atmosphere, and second only to carbon dioxide on Mars and Venus. The Voyager and Cassini-Huygens observations show that copious nitrogen is present on Titan also, comprising some 95% by volume of this moon's 1500 millibar atmosphere. After water vapor, it may be the most abundant (4%) of the gases around tiny Enceladus, as revealed by the recent Cassini observations. A thin nitrogen atmosphere is found even on the coldest of the solar system bodies, Triton and Pluto. The available evidence on nitrogen isotopes and the heavy noble gases suggests that Titan acquired its nitrogen largely in the form of ammonia. Subsequent chemical evolution, beginning with the photolysis of NH3 on primordial Titan, led to the nitrogen atmosphere we see on Titan today. This is also the scenario for the origin of nitrogen on the terrestrial planets. Contrary to Titan, the colder outer solar system objects, Triton and Pluto, neither had the luxury of receiving much arnmonia in the first place, nor of photolyzing whatever little ammonia they did receive in the planetesimals that formed them. On the other hand, it is plausible the planetesimals were capable of trapping and delivering molecular nitrogen directly to Triton and Pluto, unlike Titan. The origin of nitrogen on Enceladus is somewhat enigmatic. A scenario similar to Titan's, but with a role for the interior processes, may be at work. In this paper, we will discuss the source and loss of nitrogen for the above objects, and why Ganymede, the largest moon in the solar system, is nitrogen starved.

Interaction of Triton X-100 with acyl pocket of butyrylcholinesterase: effect on esterase activity and inhibitor sensitivity of the enzyme.

PubMed

Jaganathan, L; Boopathy, R

1998-06-01

The effect of non-ionic detergents like Triton X-100, Lubrol PX, Brij 35 and Tween 80 on the esterase activity and inhibitor sensitivity of human serum butyrylcholinesterase (BuChE) were studied. The results showed that though BuChE is not a detergent dependent enzyme, the esterase activity and inhibitor sensitivity of it can be modulated by the presence of detergents. All the detergents caused a marginal activation of the esterase activity. The presence of Lubrol PX, Brij 35 or Tween 80 did not affect the 50% molar inhibition concentration (IC50) of the inhibitors tested. But in the presence of Triton X-100 the IC50 values were increased for neostigmine, eserine and tetraisopropylpyrophosphoramide (acylation site interacting inhibitors), whereas for inhibitors like ethopropazine, imipramine and procainamide (choline binding pocket specific inhibitors) the IC50 values were unaltered. In addition, in the presence of Triton X-100 the bimolecular reaction constant for phosphorylation reaction (ki) of BuChE for the acyl pocket specific tetraisopropylpyrophosphoramide was reduced. Triton X-100 partially protected BuChE against this tetraisopropylpyrophosphoramide inactivation. These results indicate that Triton X-100 by interacting with the acyl pocket hydrophobic region is able to activate the esterase activity of BuChE. Further it reduces the capacity of the enzyme to react with inhibitors that inactivate it by interacting with the serine residue of the acylation site.

Performance variation due to stiffness in a tuna-inspired flexible foil model.

PubMed

Rosic, Mariel-Luisa N; Thornycroft, Patrick J M; Feilich, Kara L; Lucas, Kelsey N; Lauder, George V

2017-01-17

Tuna are fast, economical swimmers in part due to their stiff, high aspect ratio caudal fins and streamlined bodies. Previous studies using passive caudal fin models have suggested that while high aspect ratio tail shapes such as a tuna's generally perform well, tail performance cannot be determined from shape alone. In this study, we analyzed the swimming performance of tuna-tail-shaped hydrofoils of a wide range of stiffnesses, heave amplitudes, and frequencies to determine how stiffness and kinematics affect multiple swimming performance parameters for a single foil shape. We then compared the foil models' kinematics with published data from a live swimming tuna to determine how well the hydrofoil models could mimic fish kinematics. Foil kinematics over a wide range of motion programs generally showed a minimum lateral displacement at the narrowest part of the foil, and, immediately anterior to that, a local area of large lateral body displacement. These two kinematic patterns may enhance thrust in foils of intermediate stiffness. Stiffness and kinematics exhibited subtle interacting effects on hydrodynamic efficiency, with no one stiffness maximizing both thrust and efficiency. Foils of intermediate stiffnesses typically had the greatest coefficients of thrust at the highest heave amplitudes and frequencies. The comparison of foil kinematics with tuna kinematics showed that tuna motion is better approximated by a zero angle of attack foil motion program than by programs that do not incorporate pitch. These results indicate that open questions in biomechanics may be well served by foil models, given appropriate choice of model characteristics and control programs. Accurate replication of biological movements will require refinement of motion control programs and physical models, including the creation of models of variable stiffness.

Steel Foil Improves Performance Of Blasting Caps

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Perry, Ronnie; Schimmel, Morry L.

1990-01-01

Blasting caps, which commonly include deep-drawn aluminum cups, give significantly higher initiation performance by application of steel foils on output faces. Steel closures 0.005 in. (0.13 mm) thick more effective than aluminum. Caps with directly bonded steel foil produce fragment velocities of 9,300 ft/s (2.8 km/s) with large craters and unpredictable patterns to such degree that no attempts made to initiate explosions. Useful in military and aerospace applications and in specialized industries as mining and exploration for oil.

Shock compression response of highly reactive Ni + Al multilayered thin foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, Sean C.; Thadhani, Naresh N., E-mail: naresh.thadhani@mse.gatech.edu

2016-03-07

The shock-compression response of Ni + Al multilayered thin foils is investigated using laser-accelerated thin-foil plate-impact experiments over the pressure range of 2 to 11 GPa. The foils contain alternating Ni and Al layers (parallel but not flat) of nominally 50 nm bilayer spacing. The goal is to determine the equation of state and shock-induced reactivity of these highly reactive fully dense thin-foil materials. The laser-accelerated thin-foil impact set-up involved combined use of photon-doppler-velocimetry to monitor the acceleration and impact velocity of an aluminum flyer, and VISAR interferometry was used to monitor the back free-surface velocity of the impacted Ni + Al multilayered target. The shock-compressionmore » response of the Ni + Al target foils was determined using experimentally measured parameters and impedance matching approach, with error bars identified considering systematic and experimental errors. Meso-scale CTH shock simulations were performed using real imported microstructures of the cross-sections of the multilayered Ni + Al foils to compute the Hugoniot response (assuming no reaction) for correlation with their experimentally determined equation of state. It was observed that at particle velocities below ∼150 m/s, the experimentally determined equation of state trend matches the CTH-predicted inert response and is consistent with the observed unreacted state of the recovered Ni + Al target foils from this velocity regime. At higher particle velocities, the experimentally determined equation of state deviates from the CTH-predicted inert response. A complete and self-sustained reaction is also seen in targets recovered from experiments performed at these higher particle velocities. The deviation in the measured equation of state, to higher shock speeds and expanded volumes, combined with the observation of complete reaction in the recovered multilayered foils, confirmed via microstructure

Extraction and separation of tungsten (VI) from aqueous media with Triton X-100-ammonium sulfate-water aqueous two-phase system without any extractant.

PubMed

Yongqiang Zhang; Tichang Sun; Tieqiang Lu; Chunhuan Yan

2016-11-25

An aqueous two-phase system composed of Triton X-100-(NH 4 ) 2 SO 4 -H 2 O was proposed for extraction and separation of tungsten(VI) from aqueous solution without using any extractant. The effects of aqueous pH, concentration of ammonium sulfate, Triton X-100 and tungsten, extracting temperature on the extraction of tungsten were investigated. The extraction of tungsten has remarkable relationship with aqueous pH and are to above 90% at pH=1.0-3.0 under studied pH range (pH=1.0-7.0) and increases gradually with increasing Triton X-100 concentration, but decreases slightly with increasing ammonium sulfate concentration. The extraction percentage of tungsten is hardly relevant to temperature but its distribution coefficient linearly increases with increasing temperature within 303.15-343.15K. The distribution coefficient of tungsten increases with the increase of initial tungsten concentration (0.1-3%) and temperature (303.15 K-333.15K). The solubilization capacity of tungsten in Triton X-100 micellar phase is independent of temperature. FT-IR analysis reveals that there is no evident interaction between polytungstate anion and ether oxygen unit in Triton X-100, and DLS analysis indicates that zeta potential of Triton X-100 micellar phase have a little change from positive to negative after extracting tungsten. Based on the above-mentioned results, it can be deduced that polytungstate anions are solubilized in hydrophilic outer shell of Triton X-100 micelles by electrostatic attraction depending on its relatively high hydrophobic nature. The stripping of tungsten is mainly influenced by temperature and can be easily achieved to 95% in single stage stripping. The tungsten (VI) is separated out from solution containing Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Al(III), Cr(III) and Mn(II) under the suitable conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Method to Increase Performance of Foil Bearings Through Passive Thermal Management

NASA Technical Reports Server (NTRS)

Bruckner, Robert

2013-01-01

This invention is a new approach to designing foil bearings to increase their load capacity and improve their reliability through passive thermal management. In the present case, the bearing is designed in such a way as to prevent the carryover of lubricant from the exit of one sector to the inlet of the ensuing sector of the foil bearing. When such passive thermal management techniques are used, bearing load capacity is improved by multiples, and reliability is enhanced when compared to current foil bearings. This concept has recently been tested and validated, and shows that load capacity performance of foil bearings can be improved by a factor of two at relatively low speeds with potentially greater relative improvements at higher speeds. Such improvements in performance with respect to speed are typical of foil bearings. Additionally, operation of these newly conceived bearings shows much more reliability and repeatable performance. This trait can be exploited in machine design to enhance safety, reliability, and overall performance. Finally, lower frictional torque has been demonstrated when operating at lower (non-load capacity) loads, thus providing another improvement above the current state of the art. The objective of the invention is to incorporate features into a foil bearing that both enhance passive thermal management and temperature control, while at the same time improve the hydrodynamic (load capacity) performance of the foil bearing. Foil bearings are unique antifriction devices that can utilize the working fluid of a machine as a lubricant (typically air for turbines and motors, liquids for pumps), and as a coolant to remove excess energy due to frictional heating. The current state of the art of foil bearings utilizes forced cooling of the bearing and shaft, which represents poor efficiency and poor reliability. This invention embodies features that utilize the bearing geometry in such a manner as to both support load and provide an inherent and

Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery

NASA Astrophysics Data System (ADS)

Park, Cheol Hoon; Choi, Sang Kyu; Hong, Doo Euy; Yoon, Tae Gwang; Lee, Sung Hwi

2013-10-01

This Note proposes a novel radial-thrust combo metal mesh foil bearing (MMFB). Although MMFBs have advantages such as higher stiffness and damping over conventional air foil bearings, studies related to MMFBs have been limited to radial MMFBs. The novel combo MMFB is composed of a radial top foil, thrust top foils, and a ring-shaped metal mesh damper—fabricated by compressing a copper wire mesh—with metal mesh thrust pads for the thrust bearing at both side faces. In this study, the combo MMFB was fabricated in half-split type to support the rotor for a micro gas turbine generator. The manufacture and assembly process for the half-split-type combo MMFB is presented. In addition, to verify the proposed combo MMFB, motoring test results up to 250 000 rpm and axial displacements as a function of rotational speed are presented.

Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery.

PubMed

Park, Cheol Hoon; Choi, Sang Kyu; Hong, Doo Euy; Yoon, Tae Gwang; Lee, Sung Hwi

2013-10-01

This Note proposes a novel radial-thrust combo metal mesh foil bearing (MMFB). Although MMFBs have advantages such as higher stiffness and damping over conventional air foil bearings, studies related to MMFBs have been limited to radial MMFBs. The novel combo MMFB is composed of a radial top foil, thrust top foils, and a ring-shaped metal mesh damper--fabricated by compressing a copper wire mesh--with metal mesh thrust pads for the thrust bearing at both side faces. In this study, the combo MMFB was fabricated in half-split type to support the rotor for a micro gas turbine generator. The manufacture and assembly process for the half-split-type combo MMFB is presented. In addition, to verify the proposed combo MMFB, motoring test results up to 250,000 rpm and axial displacements as a function of rotational speed are presented.

Controlled porous pattern of anodic aluminum oxide by foils laminate approach.

PubMed

Wang, Gou-Jen; Peng, Chi-Sheng

2006-04-01

A novel, much simpler, and low-cost method to fabricate the porous pattern of the anodic aluminum oxide (AAO) based on the aluminum foils laminate approach was carried out. During our experiments, it was found that the pores of the AAO on the upper foil grew bi-directionally from both the top and the bottom surfaces. Experimental results further indicate that the upward porous pattern of the upper foil is determined by the surface structure of the bottom surface of the upper foil. The porous pattern of AAO can be controlled by a pre-made pattern on the bottom surface. Furthermore, no Aluminum (Al) layer removing process is required in this novel laminate method.

Development of thick, long-lived carbon stripper foils for PSR of LANL

NASA Astrophysics Data System (ADS)

Sugai, I.; Oyaizu, M.; Kawakami, H.; Ohmori, C.; Hattori, T.; Kawasaki, K.; Borden, M. J.; Macek, R. J.

1995-02-01

Thick carbon stripper foils (multi-layer thickness ≈ 200 μg/cm 2) have been developed for use with 800 MeV, H + ion beam in the Proton Storage Ring (PSR) at Los Alamos National Laboratory. Foils were prepared by means of the modified controlled ACDC arc discharge method (mCADAD). The lifetime measurements of the foils made by different methods were performed using an 800 MeV proton beam of up to 85 μA in the PSR, and a 3.2 MeV Ne + ion beam of 3 μA at Tokyo Institute of Technology. The foils made by the mCADAD method showed very long lifetimes, as compared to other foils tested, for both 800 MeV p and 3.2 MeV Ne + beam bombardments.

Compressor ported shroud for foil bearing cooling

DOEpatents

Elpern, David G [Los Angeles, CA; McCabe, Niall [Torrance, CA; Gee, Mark [South Pasadena, CA

2011-08-02

A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

Comparison of carbon and corrugated diamond stripper foils under operational conditions at the Los Alamos PSR

NASA Astrophysics Data System (ADS)

Spickermann, T.; Borden, M. J.; Macek, R. J.; Shaw, R. W.; Feigerle, C. S.; Sugai, I.

2008-06-01

To accumulate high-intensity proton pulses, the Los Alamos Proton Storage Ring (PSR) uses the charge-exchange injection method. H - ions merge with already circulating protons in a bending magnet, and then are stripped off their two electrons in a carbon stripper foil. The circulating protons continue to interact with the foil. Despite efforts to minimize the number of these foil hits, like "painting" of the vertical phase space, they cannot totally be eliminated. As a result, foil heating and probably also radiation damage limit the lifetime of these foils. In recent years, LANL has collaborated with KEK to improve the carbon foils in use at PSR, and these foils now last typically for about 2 months. Recently, an alternative in the form of corrugated diamond foils has been proposed for use at SNS. These foils have now been tested in PSR production for a year, and have already shown to be at least as enduring as the LANL/KEK carbon foils. Advantages of the diamond foil concept, as well as some noteworthy differences that we observed with respect to the LANL carbon foils, will be discussed here.

Measurements of Laser Generated X-ray Spectra from Irradiated Gold Foils

NASA Astrophysics Data System (ADS)

Davis, Joshua; Keiter, Paul; Drake, Paul; Klein, Sallee

2015-11-01

Soft x-ray sources may provide a means of driving photoionization fronts in materials with a Z >2. To generate these soft x-rays at a traditional UV laser facility, a gold converter foil can be implemented that absorbs the UV photons and heats up to act as a quasi-continuum blackbody emitter with a characteristic temperature of ~ 100eV. However, it takes time for the heating wave to propagate through the foil, with thicker foils having a longer delay before measureable emission is produced. Prior work has studied the emission characteristics of foil x-ray sources but was limited to laser pulses of 1ns or less. Our interest is in long duration sources (>1ns) which requires the use of thicker Au foils. To better understand how the increased foil thickness affects emission we have performed experiments at the Omega-60 laser facility studying the x-ray intensity and total emission time of 0.5, 1.0, and 2.0 μm thick gold foils driven by a 2kJ, 6ns laser pulse. This presentation will discuss the results of these experiments and will include a discussion of how these results compare with theoretical predictions. This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HEDPLP, grant No. DE-NA0001840, and the NLUF Program, grant No. DE-NA0000850, and through LLE, Univ of Rochester by the NNSA/OICF under Agreement No. DE-FC52-08NA28302.

FoilSim: Basic Aerodynamics Software Created

NASA Technical Reports Server (NTRS)

Peterson, Ruth A.

1999-01-01

FoilSim is interactive software that simulates the airflow around various shapes of airfoils. The graphical user interface, which looks more like a video game than a learning tool, captures and holds the students interest. The software is a product of NASA Lewis Research Center s Learning Technologies Project, an educational outreach initiative within the High Performance Computing and Communications Program (HPCCP).This airfoil view panel is a simulated view of a wing being tested in a wind tunnel. As students create new wing shapes by moving slider controls that change parameters, the software calculates their lift. FoilSim also displays plots of pressure or airspeed above and below the airfoil surface.

Time-varying Atmospheric Circulation Patterns Caused by N2 Condensation Flows on a Simulated Triton Atmosphere

NASA Astrophysics Data System (ADS)

Miller, C.; Chanover, N.; Murphy, J. R.; Zalucha, A. M.

2011-12-01

Triton and Pluto are two members of a possible class of bodies with an N2 frost covered surface in vapor-pressure equilibrium with a predominately N2 atmosphere. Modeling the dynamics of such an atmosphere is useful for several reasons. First, winds on Triton were inferred from images of surface streaks and active plumes visible at the time of the Voyager 2 flyby in August 1989. Dynamic atmospheric simulations can reveal the seasonal conditions under which such winds would arise and therefore how long before the Voyager 2 encounter the ground streaks may have been deposited. Second, atmospheric conditions on Pluto at the time of the New Horizons flyby are expected to be similar to those on Triton. Therefore, a dynamical model of a cold, thin N2 atmosphere can be used to predict wind speed and direction on Pluto during the New Horizons encounter with the Pluto/Charon system in July 2015. We used a modified version of the NASA Ames Mars General Circulation Model, version 2.0, to model an N2 atmosphere in contact with N2 surface frosts. We altered the Ames GCM to simulate conditions found on Triton. These alterations included changing the size, rotation rate, orbital inclination, surface gravity, and distance to the Sun of the parent body to model the proper time-varying insolation. We defined the gas properties for an N2 atmosphere, including values for latent heat, specific heat, and the vapor pressure-temperature relationship for N2 frosts. Our simulations assumed an N2 atmosphere with an initial average surface pressure of 18 microbars and we chose N2 frost albedo and emissivity values that resulted in a stable surface pressure over time. We incorporated a 190-meter deep ten-layer water-ice subsurface layer covered with a 20-centimeter global layer of N2 frost. Our simulations did not include atmospheric radiative heat transfer, but did include conduction, convection, and surface-boundary layer heating. We ran simulations of 100 Triton days at 10 points along

Measurement of the radon diffusion through a nylon foil for different air humidities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

The dependency of the radon penetration through a nylon foil on air humidity was measured. Such information is needed for the tracking part of the SuperNEMO detector, which is planned to be shielded against radon by nylon foil and in which the air humidity is not negligible. The long term measurements of radon penetration through nylon foils for different air humidities were performed with the radon diffusion setup constructed at the IEAP, CTU in Prague. The setup consists of two stainless steel hemispheres with Si detector in each of them. Both hemispheres are separated by the tested foil. While themore » left hemisphere contains high Rn activity, the right part contains only activity caused by the radon penetration through the tested foil. Obtained results of this study with a nylon foil with the thickness of 50 µm are presented.« less

Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

NASA Astrophysics Data System (ADS)

Hönnicke, M. G.; Delben, G. J.; Godoi, W. C.; Swinka-Filho, V.

2014-11-01

Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films.

Self-propulsion of a pitching foil

NASA Astrophysics Data System (ADS)

Das, Anil; Shukla, Ratnesh; Govardhan, Raghuraman

2017-11-01

Undulatory motions serve as a fundamental mechanism for bio-locomotion at moderate and high Reynolds numbers. An understanding of the interactions between self-propelling undulatory motions and the surrounding fluid, not only provides insight into the efficiency of bio-locomotion, but also yields valuable pointers for the design of autonomous under-water and micro-aerial vehicles. Here, we investigate a simplified model of a self-propelling pitching foil that undergoes time-periodic oscillations about its quarter chord. We consider two-dimensional configurations in which the foil is free to propel along only longitudinal and both transverse and longitudinal directions. In both the configurations, the time-averaged self-propelling velocity increases monotonically with the Reynolds number Re (based on trailing edge speed and chord as the characteristic velocity and length). The rate of increase is particularly pronounced in the low Re regime (Re <400) over which the closely-spaced wake vortices dissipate within a few chord lengths. At moderate and high Re, the wake exhibits increasingly complex structure in both the configurations. For a fixed Re, the foil with a single translational degree of freedom propels at a higher speed for a higher input power requirement. Differences between the two configurations will be discussed within the context of undulatory self-propulsion observed in nature.

Goal-directed mechanisms that constrain retrieval predict subsequent memory for new "foil" information.

PubMed

Vogelsang, David A; Bonnici, Heidi M; Bergström, Zara M; Ranganath, Charan; Simons, Jon S

2016-08-01

To remember a previous event, it is often helpful to use goal-directed control processes to constrain what comes to mind during retrieval. Behavioral studies have demonstrated that incidental learning of new "foil" words in a recognition test is superior if the participant is trying to remember studied items that were semantically encoded compared to items that were non-semantically encoded. Here, we applied subsequent memory analysis to fMRI data to understand the neural mechanisms underlying the "foil effect". Participants encoded information during deep semantic and shallow non-semantic tasks and were tested in a subsequent blocked memory task to examine how orienting retrieval towards different types of information influences the incidental encoding of new words presented as foils during the memory test phase. To assess memory for foils, participants performed a further surprise old/new recognition test involving foil words that were encountered during the previous memory test blocks as well as completely new words. Subsequent memory effects, distinguishing successful versus unsuccessful incidental encoding of foils, were observed in regions that included the left inferior frontal gyrus and posterior parietal cortex. The left inferior frontal gyrus exhibited disproportionately larger subsequent memory effects for semantic than non-semantic foils, and significant overlap in activity during semantic, but not non-semantic, initial encoding and foil encoding. The results suggest that orienting retrieval towards different types of foils involves re-implementing the neurocognitive processes that were involved during initial encoding. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Incapacity of Response to Disulfide-Reducing Agent in Triton X-100-Treated Oocytes of Starfish, Asterina pectinifera

NASA Astrophysics Data System (ADS)

Mita, Masatoshi

2005-04-01

Resumption of meiosis in starfish oocytes is induced by the natural maturation-inducing hormone, 1-methyladenine (1-MeAde). Oocyte maturation is also induced by the disulfide-reducing agent, dithiothreitol (DTT). Previous studies have shown that 1-MeAde controls meiosis by interacting with its receptors, which are located exclusively on oocyte plasma membrane. However, little is known about the mechanism of oocyte maturation induced by DTT. Thus, this study examined whether DTT interacts with 1-MeAde receptors to induce oocyte maturation. When oocytes were treated with Triton X-100, they failed to respond to 1-MeAde and DTT. Although the Triton X-100-treated oocytes recovered the capacity to respond to 1-MeAde during incubation in seawater, they remained unresponsive to DTT during seawater incubations. These results suggest that DTT does not interact with 1-MeAde receptors to induce oocyte maturation in starfish. It is possible that a protein essential for mediating DTT-induced maturation is eliminated from the oocytes surface following Triton X-100 treatment.

Precise CCD positions of Triton in 2014-2016 from the Gaia DR1

NASA Astrophysics Data System (ADS)

Wang, N.; Peng, Q. Y.; Peng, H. W.; Zhang, Q. F.

2018-04-01

755 CCD observations during the years 2014-2016 have been reduced to derive the precise positions of Triton, the first satellite of Neptune. The observations were made by the 1 m telescope at Yunnan Observatory over 15 nights during the years 2014-2016. The theoretical position of Triton was retrieved from the Jet Propulsion Laboratory Horizons system. Our results show that when the newest Gaia catalogue (Gaia DR1) is referred to the mean O-Cs (observed minus computed) residuals are about 0.042 and -0.006 arcsec, the dispersions are 0.012 and 0.012 arcsec in right ascension and declination, respectively. The dispersions are improved very significantly when the Gaia DR1 is referred to. However, the agreement in right ascension is not so good as that in declination, the reason might come from the uncertainty of planet ephemeris. More observations are needed to confirm this.

Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulthess, Jason

2014-09-01

Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

Stripper foil failure modes and cures at the Spallation Neutron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cousineau, Sarah M; Galambos, John D; Kim, Sang-Ho

2011-01-01

The Spallation Neutron Source comprises a 1 GeV, 1.4 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the $H^0$ excited states created during the $H^-$ charge exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming $H^-$ beam, which circled around to strike the foilmore » bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we detail these and other interesting failure mechanisms and describe the improvements we have made to mitigate them.« less

Dynamics and locomotion of flexible foils in a frictional environment

NASA Astrophysics Data System (ADS)

Wang, Xiaolin; Alben, Silas

2018-01-01

Over the past few decades, oscillating flexible foils have been used to study the physics of organismal propulsion in different fluid environments. Here, we extend this work to a study of flexible foils in a frictional environment. When the foil is oscillated by heaving at one end but is not free to locomote, the dynamics change from periodic to non-periodic and chaotic as the heaving amplitude increases or the bending rigidity decreases. For friction coefficients lying in a certain range, the transition passes through a sequence of N-periodic and asymmetric states before reaching chaotic dynamics. Resonant peaks are damped and shifted by friction and large heaving amplitudes, leading to bistable states. When the foil is free to locomote, the horizontal motion smoothes the resonant behaviours. For moderate frictional coefficients, steady but slow locomotion is obtained. For large transverse friction and small tangential friction corresponding to wheeled snake robots, faster locomotion is obtained. Travelling wave motions arise spontaneously, and move with horizontal speeds that scale as transverse friction coefficient to the power 1/4 and input power that scales as the transverse friction coefficient to the power 5/12. These scalings are consistent with a boundary layer form of the solutions near the foil's leading edge.

Dynamics and locomotion of flexible foils in a frictional environment.

PubMed

Wang, Xiaolin; Alben, Silas

2018-01-01

Over the past few decades, oscillating flexible foils have been used to study the physics of organismal propulsion in different fluid environments. Here, we extend this work to a study of flexible foils in a frictional environment. When the foil is oscillated by heaving at one end but is not free to locomote, the dynamics change from periodic to non-periodic and chaotic as the heaving amplitude increases or the bending rigidity decreases. For friction coefficients lying in a certain range, the transition passes through a sequence of N -periodic and asymmetric states before reaching chaotic dynamics. Resonant peaks are damped and shifted by friction and large heaving amplitudes, leading to bistable states. When the foil is free to locomote, the horizontal motion smoothes the resonant behaviours. For moderate frictional coefficients, steady but slow locomotion is obtained. For large transverse friction and small tangential friction corresponding to wheeled snake robots, faster locomotion is obtained. Travelling wave motions arise spontaneously, and move with horizontal speeds that scale as transverse friction coefficient to the power 1/4 and input power that scales as the transverse friction coefficient to the power 5/12. These scalings are consistent with a boundary layer form of the solutions near the foil's leading edge.

The target-to-foils shift in simultaneous and sequential lineups.

PubMed

Clark, Steven E; Davey, Sherrie L

2005-04-01

A theoretical cornerstone in eyewitness identification research is the proposition that witnesses, in making decisions from standard simultaneous lineups, make relative judgments. The present research considers two sources of support for this proposal. An experiment by G. L. Wells (1993) showed that if the target is removed from a lineup, witnesses shift their responses to pick foils, rather than rejecting the lineups, a result we will term a target-to-foils shift. Additional empirical support is provided by results from sequential lineups which typically show higher accuracy than simultaneous lineups, presumably because of a decrease in the use of relative judgments in making identification decisions. The combination of these two lines of research suggests that the target-to-foils shift should be reduced in sequential lineups relative to simultaneous lineups. Results of two experiments showed an overall advantage for sequential lineups, but also showed a target-to-foils shift equal in size for simultaneous and sequential lineups. Additional analyses indicated that the target-to-foils shift in sequential lineups was moderated in part by an order effect and was produced with (Experiment 2) or without (Experiment 1) a shift in decision criterion. This complex pattern of results suggests that more work is needed to understand the processes which underlie decisions in simultaneous and sequential lineups.

Antioxidant capacity of pure compounds and complex mixtures evaluated by the ORAC-pyrogallol red assay in the presence of Triton X-100 micelles.

PubMed

Romero, Max; Rojano, Benjamin; Mella-Raipán, Jaime; Pessoa-Mahana, Carlos David; Lissi, Eduardo; López-Alarcón, Camilo

2010-09-01

The protective effect of different antioxidants and complex mixtures on the consumption of pyrogallol red (PGR) induced by peroxyl radicals was studied in the absence and presence of Triton X-100 micelles. The presence of micelles decreased significantly the protection of PGR afforded by lipophilic antioxidants (β-carotene, octyl gallate), while no effect of micelles was observed for hydrophilic antioxidants such as Trolox, caffeic acid, gallic acid, and ascorbic acid. In the presence of complex mixtures a clear effect of Triton X-100 micelles was also observed in the protection afforded by wines, tea infusions, and seed extracts of Eugenia jambolana and Myrciaria cauliflora. On the other hand, no effect of micelles was observed for orange juice and pulp fruit extracts. The ORAC (Oxygen Radical Absorbance Capacity) index was evaluated in the absence (ORAC-PGR) and presence of Triton X-100 micelles (ORAC-PGR(MIC)). Triton X-100 micelles affect ORAC-PGR values of antioxidants in a lipophilicity-dependent way. From the obtained results, we conclude that ORAC-PGR and ORAC-PGR(MIC) assays could be considered as an alternative to estimate the antioxidant ability (ORAC-PGR) and to infer the association to Triton X-100 micelles (ORAC-PGR/ORAC-PGR(MIC)) of pure antioxidants and their complex mixtures.

Characteristics of a plasma flow field produced by a metal array bridge foil explosion

NASA Astrophysics Data System (ADS)

Junying, WU; Long, WANG; Yase, LI; Lijun, YANG; Manzoor, SULTAN; Lang, CHEN

2018-07-01

To improve the energy utilization efficiency of metal bridge foil explosion, and increase the function range of plasmas, array bridge foil explosion experiments with different structures were performed. A Schlieren photographic measurement system with a double-pulse laser source was used to observe the flow field of a bridge foil explosion. The evolution laws of plasmas and shock waves generated by array bridge foil explosions of different structures were analyzed and compared. A multi-phase flow calculation model was established to simulate the electrical exploding process of a metal bridge foil. The plasma equation of state was determined by considering the effect of the changing number of particles and Coulomb interaction on the pressure and internal energy. The ionization degree of the plasma was calculated via the Saha–Eggert equation assuming conditions of local thermal equilibrium. The exploding process of array bridge foils was simulated, and the superposition processes of plasma beams were analyzed. The variation and distribution laws of the density, temperature, pressure, and other important parameters were obtained. The results show that the array bridge foil has a larger plasma jet diameter than the single bridge foil for an equal total area of the bridge foil. We also found that the temperature, pressure, and density of the plasma jet’s center region sharply increase because of the superposition of plasma beams.

The effect of chordwise flexibility on flapping foil propulsion in quiescent fluid

NASA Astrophysics Data System (ADS)

Shinde, Sachin; Arakeri, Jaywant

2010-11-01

Motivated to understand the role of wing flexibility of flying creatures during hovering, we experimentally study the effect of chordwise flexibility on the flow generated in quiescent fluid by a sinusoidally pitching rigid symmetrical foil with a flexible flap attached at the trailing edge. This foil produces a narrow, coherent jet containing reverse Karman vortex street, and a corresponding thrust. The thrust and flow is similar to that produced by a hovering bird or insect, however the mechanism seems to be different from known hovering mechanisms. Novelty of the present hovering mechanism is that the thrust generation is due to the coordinated pushing action of rigid foil and flexible flap. We identify the flow and vortex generation mechanism. This foil produces jet flows over a range of flapping frequencies and amplitudes. In contrast, the foil without flap i.e. with rigid trailing edge produces a weak, divergent jet that meanders randomly. Appending a flexible flap to the foil suppresses jet-meandering and strengthens the jet. Flexibility of flap is crucial in determining the flow structure. This study is useful in designing MAVs and thrusters.

Scattering effects in passive foil focusing of ion beams

DOE PAGES

Yuen, Albert; Lund, Steven M.; Barnard, John J.; ...

2015-09-11

A stack of thin, closely spaced conducting foils has been investigated by Lund et al. [ Phys. Rev. ST Accel. Beams 16, 044202 (2013)] as a passive focusing lens for intense ion beams. The foils mitigate space-charge defocusing forces to enable the beam self-magnetic field to focus. In this study, we analyze possible degradation of focusing due to scattering of beam ions resulting from finite foil thickness using an envelope model and numerical simulations with the particle-in-cell code WARP. Ranges of kinetic energy where scattering effects are sufficient to destroy passive focusing are quantified. The scheme may be utilized tomore » focus protons produced in intense laser-solid accelerator schemes. The spot size of an initially collimated 30 MeV proton beam with initial rms radius 200 μm, perveance Q=1.8×10 -2, and initial transverse emittance ϵ x,rms=0.87 mm mrad propagating through a stack of 6.4 μm thick foils, spaced 100 μm apart, gives a 127.5 μm spot with scattering and a 81.0 μm spot without scattering, illustrating the importance of including scattering effects.« less

Comparison of fluence-to-dose conversion coefficients for deuterons, tritons and helions.

PubMed

Copeland, Kyle; Friedberg, Wallace; Sato, Tatsuhiko; Niita, Koji

2012-02-01

Secondary radiation in aircraft and spacecraft includes deuterons, tritons and helions. Two sets of fluence-to-effective dose conversion coefficients for isotropic exposure to these particles were compared: one used the particle and heavy ion transport code system (PHITS) radiation transport code coupled with the International Commission on Radiological Protection (ICRP) reference phantoms (PHITS-ICRP) and the other the Monte Carlo N-Particle eXtended (MCNPX) radiation transport code coupled with modified BodyBuilder™ phantoms (MCNPX-BB). Also, two sets of fluence-to-effective dose equivalent conversion coefficients calculated using the PHITS-ICRP combination were compared: one used quality factors based on linear energy transfer; the other used quality factors based on lineal energy (y). Finally, PHITS-ICRP effective dose coefficients were compared with PHITS-ICRP effective dose equivalent coefficients. The PHITS-ICRP and MCNPX-BB effective dose coefficients were similar, except at high energies, where MCNPX-BB coefficients were higher. For helions, at most energies effective dose coefficients were much greater than effective dose equivalent coefficients. For deuterons and tritons, coefficients were similar when their radiation weighting factor was set to 2.

Triton College 1999 NCA Self-Study Report. Prepared for the North Central Association of Colleges and Schools Commission on Institutions of Higher Education.

ERIC Educational Resources Information Center

Triton Coll., River Grove, IL.

The primary purpose of this report is to demonstrate that Triton College meets the North Central Association's (NCA's) twenty-four General Institutional Requirements and satisfies NCA's five criteria of Educational Excellence. To achieve this goal, the report presents a comprehensive picture of Triton College's mission, organization, programs, and…

Measurements of confined alphas and tritons in the MHD quiescent core of TFTR plasmas using the pellet charge exchange diagnostic

NASA Astrophysics Data System (ADS)

Medley, S. S.; Budny, R. V.; Mansfield, D. K.; Redi, M. H.; Roquemore, A. L.; Fisher, R. K.; Duong, H. H.; McChesney, J. M.; Parks, P. B.; Petrov, M. P.; Gorelenkov, N. N.

1996-10-01

The energy distributions and radial density profiles of the fast confined trapped alpha particles in DT experiments on TFTR are being measured in the energy range 0.5 - 3.5 MeV using the pellet charge exchange (PCX) diagnostic. A brief description of the measurement technique which involves active neutral particle analysis using the ablation cloud surrounding an injected impurity pellet as the neutralizer is presented. This paper focuses on alpha and triton measurements in the core of MHD quiescent TFTR discharges where the expected classical slowing-down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. In particular, the first measurement of the alpha slowing-down distribution up to the birth energy, obtained using boron pellet injection, is presented. The measurements are compared with predictions using either the TRANSP Monte Carlo code and/or a Fokker - Planck Post-TRANSP processor code, which assumes that the alphas and tritons are well confined and slow down classically. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with the code calculations. We can conclude that the PCX measurements are consistent with classical thermalization of the fusion-generated alphas and tritons.

Proactive interference and cuing effects in short-term cued recall: does foil context matter?

PubMed

Goh, Winston D; Tan, Huiqin

2006-07-01

Tehan and Humphreys's (1995, 1996) short-term cued recall paradigm showed that recall in short-term memory is cue driven. In critical trials, the participants studied two blocks of four words each and were required to forget the first block while remembering the second block. A foil in the first block (e.g., orange) was related to a target (e.g., carrot) in the second block. Proactive interference (PI) was evident when a retrieval cue was used that subsumed the foil and the target (e.g., type of juice), but not when a cue was used that subsumed only the target (e.g., type of vegetable). Four experiments were performed to examine the extent to which contextual organization in the foil block would enhance or diminish the foil's efficacy in creating PI. A novel condition was included in which the words in the foil block were studied in a phonologically related context but the target was cued semantically, and vice versa with a semantic context and phonological cue. There were no differences in recall accuracy between conditions with and without contextual organization, but reliable increases in foil intrusions were observed when contextual organization was present. Contextual organization enhanced the foil, rather than diminished it, but the strengthened foil generated PI only when the cue subsumed the foil and the target and had no effect when the cue subsumed only the target. The results are consistent with a cue-driven retrieval interpretation of short-term recall.

Double-layer effects on the lifetime of newly developed HBC-foils for RCS of J-PARC

NASA Astrophysics Data System (ADS)

Sugai, I.; Takeda, Y.; Oyaizu, M.; Kawakami, H.; Irie, Y.; Takagi, A.; Hattori, H.; Kawasaki, K.

2010-02-01

We have developed hybrid type boron-mixed carbon (HBC) foils for the rapid cycling synchrotron (RCS) of Japan-proton accelerator research complex (J-PARC) using the controlled DC arc-discharge method. The method has been found suitable for the production of thick foils up to a maximum of 700 μg/cm 2 due to the strong adhesion to the substrate. The foils thus produced showed rather long lifetime. By the development, high-temperature damage (foil deformation, thickness reduction and pinhole formation) of the foil was significantly mitigated even at a temperature of approximately 1700 K. However, when the foil temperature was higher than about 1800 K, especially pinhole formation in the irradiated area of the foil and its peripheries were always observed. In order to relieve high-temperature damage, we investigated the possibility to lower the temperature rise in single and double layer HBC-foils while keeping the total thickness the same. We also compared the lifetime of the single and the double layer HBC-foils as well as diamond and commercially available foils, using a 3.2 MeV Ne + ion beam from the Van de Graaff accelerator.

Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

PubMed Central

Góngora-Rubio, Mário R.; Kiyono, César Y.; Mello, Luis A. M.; Cardoso, Valtemar F.; Rosa, Reinaldo L. S.; Kuebler, Derek A.; Brodeur, Grace E.; Alotaibi, Amani H.; Coene, Marisa P.; Coene, Lauren M.; Jean, Elizabeth; Santiago, Rafael C.; Oliveira, Francisco H. A.; Rangel, Ricardo; Thomas, Gilles P.; Belay, Kalayu; da Silva, Luciana W.; Moura, Rafael T.; Seabra, Antonio C.; Silva, Emílio C. N.

2018-01-01

Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more. PMID:29401745

An Oil-Free Thrust Foil Bearing Facility Design, Calibration, and Operation

NASA Technical Reports Server (NTRS)

Bauman, Steve

2005-01-01

New testing capabilities are needed in order to foster thrust foil air bearing technology development and aid its transition into future Oil-Free gas turbines. This paper describes a new test apparatus capable of testing thrust foil air bearings up to 100 mm in diameter at speeds to 80,000 rpm and temperatures to 650 C (1200 F). Measured parameters include bearing torque, load capacity, and bearing temperatures. This data will be used for design performance evaluations and for validation of foil bearing models. Preliminary test results demonstrate that the rig is capable of testing thrust foil air bearings under a wide range of conditions which are anticipated in future Oil-Free gas turbines. Torque as a function of speed and temperature corroborates results expected from rudimentary performance models. A number of bearings were intentionally failed with no resultant damage whatsoever to the test rig. Several test conditions (specific speeds and loads) revealed undesirable axial shaft vibrations which have been attributed to the magnetic bearing control system and are under study. Based upon these preliminary results, this test rig will be a valuable tool for thrust foil bearing research, parametric studies and technology development.

Experimental Investigation of the Electrothermal Instability on Planar Foil Ablation Experiments

NASA Astrophysics Data System (ADS)

Steiner, Adam; Patel, Sonal; Yager-Elorriaga, David; Jordan, Nicholas; Gilgenbach, Ronald; Lau, Y. Y.

2014-10-01

The electrothermal instability (ETI) is an important early-time physical effect on pulsed power foil ablation experiments due to its ability to seed the destructive magneto-Rayleigh-Taylor (MRT) instability. ETI occurs whenever electrical resistivity has temperature dependence; when resistivity increases with temperature, as with solid metal liners or foils, ETI forms striation structures perpendicular to current flow. These striations provide an initial perturbation for the MRT instability, which is the dominant late-time instability in planar foil ablations. The MAIZE linear transformer driver was used to drive current pulses of approximately 600 kA into 400 nm-thick aluminum foils in order to study ETI in planar geometry. Shadowgraph images of the aluminum plasmas were taken for multiple shots at various times within approximately 50 ns of current start. Fourier analysis extracted the approximate wavelengths of the instability structures on the plasma-vacuum interface. Surface metrology of pre-shot foils was performed to provide a comparison between surface roughness features and resulting plasma structure. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant # DGE 1256260.

Stripper foil failure modes and cures at the Oak Rdige Spallation Neutron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plum, M.A.; Raparia, D.; Cousineau, S.M.

2011-03-28

The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H{sup 0} excited states created during the H{sup -} charge-exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming H{sup -} beam, which circled aroundmore » to strike the foil bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we detail these and other interesting failure mechanisms and describe the improvements we have made to mitigate them.« less

Brazing Inconel 625 Using the Copper Foil

NASA Astrophysics Data System (ADS)

Chen, Wen-Shiang; Wang, Cheng-Yen; Shiue, Ren-Kae

2013-12-01

Brazing Inconel 625 (IN-625) using the copper foil has been investigated in this research. The brazed joint is composed of nanosized CrNi3 precipitates and Cr/Mo/Nb/Ni quaternary compound in the Cu/Ni-rich matrix. The copper filler 50 μm in thickness is enough for the joint filling. However, the application of Cu foil 100 μm in thickness has little effect on the shear strength of the brazed joint. The specimen brazed at 1433 K (1160 °C) for 1800 seconds demonstrates the best shear strength of 470 MPa, and its fractograph is dominated by ductile dimple fracture with sliding marks. Decreasing the brazing temperature slightly decreases the shear strength of the brazed joint due to the presence of a few isolated solidification shrinkage voids smaller than 15 μm. Increasing the brazing temperature, especially for the specimen brazed at 1473 K (1200 °C), significantly deteriorates the shear strength of the joint below 260 MPa because of coalescence of isothermal solidification shrinkage voids in the joint. The Cu foil demonstrates potential in brazing IN-625 for industrial application.

Development of damage suppression system using embedded SMA foil in CFRP laminates

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Kobayashi, Masakazu; Okabe, Tomonaga; Takeda, Nobuo

2001-07-01

Some recent studies have suggested possible applications of Shape Memory Alloy (SMA) for a smart health monitoring and suppression of damage growth. The authors have been conducting research and development studies on applications of embedded SMA foil actuators in CFRP laminates as the basic research for next generation aircrafts. First the effective surface treatment for improvement of bonding properties between SMA and CFRP was studied. It was certified that the anodic oxide treatment by 10% NaOH solution was the most effective treatment from the results of peel resistance test and shear strength test. Then, CFRP laminates with embedded SMA foils were successfully fabricated using this effective surface treatment. The damage behavior of quasi-isotropic CFRP laminates with embedded SMA foils was characterized in both quasi-static load-unload and fatigue tests. The relationship between crack density and applied strain was obtained. The recovery stress generated by embedded SMA foils could increase the onset strain of transverse cracking by 0.2%. The onset strain of delmination in CFRP laminates was also increased accordingly. The shear-lag analysis was also conducted to predict the damage evolution in CFRP laminates with embedded SMA foils. The adhesive layers on both sides of SMA foils were treated as shear elements. The theoretical analysis successfully predicted the experimental results.

Improvements in Fabrication of Elastic Scattering Foils Used to Measure Neutron Yield by the Magnetic Recoil Spectrometer

DOE PAGES

Reynolds, H. G.; Schoff, M. E.; Farrell, M. P.; ...

2017-03-23

The magnetic recoil spectrometer uses a deuterated polyethylene polymer (CD 2) foil to measure neutron yield in inertial confinement fusion experiments. Higher neutron yields in recent experiments have resulted in primary signal saturation in the detector CR-39 foils, necessitating the fabrication of thinner CD 2 foils than established methods could provide. A novel method of fabricating deuterated polymer foils is described. The resulting foils are thinner, smoother, and more uniform in thickness than the foils produced by previous methods. Here, these new foils have successfully been deployed at the National Ignition Facility, enabling higher neutron yield measurements than previous foils,more » with no primary signal saturation.« less

75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-12

... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...

Conceptual Design and Feasibility of Foil Bearings for Rotorcraft Engines: Hot Core Bearings

NASA Technical Reports Server (NTRS)

Howard, Samuel A.

2007-01-01

Recent developments in gas foil bearing technology have led to numerous advanced high-speed rotating system concepts, many of which have become either commercial products or experimental test articles. Examples include oil-free microturbines, motors, generators and turbochargers. The driving forces for integrating gas foil bearings into these high-speed systems are the benefits promised by removing the oil lubrication system. Elimination of the oil system leads to reduced emissions, increased reliability, and decreased maintenance costs. Another benefit is reduced power plant weight. For rotorcraft applications, this would be a major advantage, as every pound removed from the propulsion system results in a payload benefit.. Implementing foil gas bearings throughout a rotorcraft gas turbine engine is an important long-term goal that requires overcoming numerous technological hurdles. Adequate thrust bearing load capacity and potentially large gearbox applied radial loads are among them. However, by replacing the turbine end, or hot section, rolling element bearing with a gas foil bearing many of the above benefits can be realized. To this end, engine manufacturers are beginning to explore the possibilities of hot section gas foil bearings in propulsion engines. This overview presents a logical follow-on activity by analyzing a conceptual rotorcraft engine to determine the feasibility of a foil bearing supported core. Using a combination of rotordynamic analyses and a load capacity model, it is shown to be reasonable to consider a gas foil bearing core section. In addition, system level foil bearing testing capabilities at NASA Glenn Research Center are presented along with analysis work being conducted under NRA Cooperative Agreements.

Design, Fabrication and Performance of Open Source Generation I and II Compliant Hydrodynamic Gas Foil Bearings

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

2007-01-01

Foil gas bearings are self-acting hydrodynamic bearings made from sheet metal foils comprised of at least two layers. The innermost top foil layer traps a gas pressure film that supports a load while a layer or layers underneath provide an elastic foundation. Foil bearings are used in many lightly loaded, high-speed turbo-machines such as compressors used for aircraft pressurization, and small micro-turbines. Foil gas bearings provide a means to eliminate the oil system leading to reduced weight and enhanced temperature capability. The general lack of familiarity of the foil bearing design and manufacturing process has hindered their widespread dissemination. This paper reviews the publicly available literature to demonstrate the design, fabrication and performance testing of both first and second generation bump style foil bearings. It is anticipated that this paper may serve as an effective starting point for new development activities employing foil bearing technology.

Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications

NASA Technical Reports Server (NTRS)

Radil, Kevin C.; DellaCorte, Christopher

2009-01-01

Foil gas bearings under development for rotorcraft-sized, hot core engine applications have been susceptible to damage from the slow acceleration and rates typically encountered during the pre-ignition stage in conventional engines. Recent laboratory failures have been assumed to be directly linked to operating foil bearings below their lift-off speed while following conventional startup procedures for the engines. In each instance, the continuous sliding contact between the foils and shaft was believed to thermally overload the bearing and cause the engines to fail. These failures highlight the need to characterize required acceleration rates and minimum operating speeds for these applications. In this report, startup experiments were conducted with a large, rotorcraft engine sized foil bearing under moderate load and acceleration rates to identify the proper start procedures needed to avoid bearing failure. The results showed that a bearing under a 39.4 kPa static load can withstand a modest acceleration rate of 500 rpm/s and excessive loitering below the bearing lift-off speed provided an adequate solid lubricant is present.

Design, fabrication, and performance of foil journal bearing for the brayton rotating unit

NASA Technical Reports Server (NTRS)

Licht, L.; Branger, M.

1973-01-01

Foil bearings were designed and manufactured to replace pivoted-shoe journal bearings in an existing Brayton Cycle turbo-alternator-compressor. The design of this unconventional rotor support was accomplished within the constraints and space limitations imposed by the present machine, and the substitution of foil bearings was effected without changes or modification other machine components. A housing and a test rig were constructed to incorporate the new foil-bearing support into a unified assemble with an air-driven rotor and the gimbal-mounted thrust bearing, seals, and shrouds of an actual Brayton Rotating Unit. The foil bearing required no external pressure source, and stable self-acting rotation was achieved at all speeds up to 43,200 rpm. Excellent wipe-wear characteristics of the foil bearing permitted well over 1000 start-stop cycles with no deterioriation of performance in the entire speed range.

Preparation and comparative testing of advanced diamond-like carbon foils for tandem accelerators and time-of-flight spectrometers

NASA Astrophysics Data System (ADS)

Liechtenstein, V. Kh.; Ivkova, T. M.; Olshanski, E. D.; Baranov, A. M.; Repnow, R.; Hellborg, R.; Weller, R. A.; Wirth, H. L.

1999-12-01

The sputter preparation technique for thin diamond-like carbon (DLC) foils, advantageously used for ion-beam stripping and timing in accelerator experiments, has been optimized to improve the quality and the performance of the foils. Irradiation lifetimes of 5 μg/cm 2 DLC foils prepared by this technique have been compared with those for foils of approximately the same thickness, prepared by laser plasma ablation and for ethylene cracked foils when bombarded by 11 MeV Cu - - and Au --ion beams of ˜1 μA beam current at the Heidelberg MP-tandem. Standard carbon arc-evaporated foils were used as references. In these experiments, DLC stripper foils appeared to have a mean lifetime approximately two times longer than ethylene-cracked foils regardless of ion species, and compared favorably with foils prepared by laser ablation method. All these foils lasted at least, 10 times longer than standard carbon foils, when irradiated in the MP terminal. Approximately, the same improvement factor was confirmed with 3 μg/cm 2 DLC stripper foils irradiated with 2.3 MeV Ni-beams at the Pelletron accelerator in Lund. Unlike standard carbon foils, most of the advanced lifetime foils exhibited thinning during long irradiation, under clean vacuum. This suggests that sputtering of the foil by the heavy-ion beam might be a dominant process, responsible for the observed failure of these long-lived strippers. Along with specifically corrugated self-supporting DLC beam strippers, we succeeded in the fabrication of very smooth and ultra thin (˜0.5 μg/cm 2) DLC foils, mounted on grids and used as start foils for the ToF spectrometers applied in ion beam analysis.

Slowing down of 100 keV antiprotons in Al foils

NASA Astrophysics Data System (ADS)

Nordlund, K.

2018-03-01

Using energy degrading foils to slow down antiprotons is of interest for producing antihydrogen atoms. I consider here the slowing down of 100 keV antiprotons, that will be produced in the ELENA storage ring under construction at CERN, to energies below 10 keV. At these low energies, they are suitable for efficient antihydrogen production. I simulate the antihydrogen motion and slowing down in Al foils using a recently developed molecular dynamics approach. The results show that the optimal Al foil thickness for slowing down the antiprotons to below 5 keV is 910 nm, and to below 10 keV is 840 nm. Also the lateral spreading of the transmitted antiprotons is reported and the uncertainties discussed.

A rare case of malignant triton tumor in the cerebellopontine angle.

PubMed

Gong, Li; Liu, Xiao-Yan; Zhang, Wen-Dong; Han, Xiu-Juan; Yao, Li; Zhu, Shao-Jun; Lan, Miao; Li, Yan-Hong; Zhang, Wei

2012-04-19

Malignant triton tumor (MTT) is defined as malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Intracranial MTT is extremely rare, and only four cases have been reported in the literature. Here, we report a case of MTT occurring in the cerebellopontine angle, and describe its histopathological characteristics, immunohistochemical features, and prognosis. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1336227313684480.

Bacterial properties changing under Triton X-100 presence in the diesel oil biodegradation systems: from surface and cellular changes to mono- and dioxygenases activities.

PubMed

Sałek, Karina; Kaczorek, Ewa; Guzik, Urszula; Zgoła-Grześkowiak, Agnieszka

2015-03-01

Triton X-100, as one of the most popular surfactants used in bioremediation techniques, has been reported as an effective agent enhancing the biodegradation of hydrocarbons. However efficient, the surfactant's role in different processes that together enable the satisfying biodegradation should be thoroughly analysed and verified. In this research, we present the interactions of Triton X-100 with the bacterial surfaces (hydrophobicity and zeta potential), its influence on the enzymatic properties (considering mono- and dioxygenases) and profiles of fatty acids, which then all together were compared with the biodegradation rates. The addition of various concentrations of Triton X-100 to diesel oil system revealed different cell surface hydrophobicity (CSH) of the tested strains. The results demonstrated that for Pseudomonas stutzeri strain 9, higher diesel oil biodegradation was correlated with hydrophilic properties of the tested strain and lower Triton X-100 biodegradation. Furthermore, an increase of the branched fatty acids was observed for this strain.

Foil bearing performance in liquid nitrogen and liquid oxygen

NASA Technical Reports Server (NTRS)

Genge, Gary G.; Saville, Marshall; Gu, Alston

1993-01-01

Space transfer vehicles and other power and propulsion systems require long-life turbopumps. Rolling-element bearings used in current turbopumps do not have sufficient life for these applications. Process fluid foil bearings have established long life, with exceptional reliability, over a wide range of temperatures and fluids in many high-speed turbomachinery applications. However, actual data on bearing performance in cryogenic fluids has been minimal. The National Aeronautics and Space Administration (NASA) and AlliedSignal Aerospace Systems and Equipment (ASE) have attempted to characterize the leaf-type compliant foil bearing in oxygen and nitrogen. The work performed under a joint internal research and development program between Marshall Space Flight Center (MSFC) and ASE demonstrated that the foil bearing has load capacities of at least 266 psi in liquid oxygen and 352 psi in liquid nitrogen. In addition, the bearing demonstrated a direct damping coefficient of 40 to 50 lb-sec/in. with a damping ratio of .7 to 1.4 in. liquid nitrogen using a bearing sized for upper-stage turbopumps. With the results from this testing and the years of successful use in air cycle machines and other applications, leaf-type compliant foil bearings are ready for testing in liquid oxygen turbopumps.

Wake visualization of a heaving and pitching foil in a soap film

NASA Astrophysics Data System (ADS)

Muijres, Florian T.; Lentink, David

2007-11-01

Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a two-dimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with thickness variations in the soap film, which appear as interference fringes when the film is illuminated with a monochromatic light source (we used a high-frequency SOX lamp). These interference fringes are subsequently captured with high-speed video (500 Hz) and this allows us to study the unsteady vortical field of a flapping foil. The main advantage of our approach is that the flow fields are time and space resolved and can be obtained time-efficiently. The foil is driven by a flapping mechanism that is optimized for studying both fish swimming and insect flight inside and outside the behavioral envelope. The mechanism generates sinusoidal heave and pitch kinematics, pre-described by the non-dimensional heave amplitude (0-6), the pitch amplitude (0°-90°), the phase difference between pitch and heave (0°-360°), and the dimensionless wavelength of the foil (3-18). We obtained this wide range of wavelengths for a foil 4 mm long by minimizing the soap film speed (0.25 m s-1) and maximizing the flapping frequency range (4-25 Hz). The Reynolds number of the foil is of order 1,000 throughout this range. The resulting setup enables an effective assessment of vortex wake topology as a function of flapping kinematics. The efficiency of the method is further improved by carefully eliminating background noise in the visualization (e.g., reflections of the mechanism). This is done by placing mirrors at an angle behind the translucent film such that the camera views the much more distant and out-of-focus reflections of the black laboratory wall. The resulting high-quality flow visualizations require minimal image processing for flow interpretation. Finally, we demonstrate the

Wake visualization of a heaving and pitching foil in a soap film

NASA Astrophysics Data System (ADS)

Muijres, Florian T.; Lentink, David

Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a twodimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with thickness variations in the soap film, which appear as interference fringes when the film is illuminated with a monochromatic light source (we used a high-frequency SOX lamp). These interference fringes are subsequently captured with high-speed video (500 Hz) and this allows us to study the unsteady vortical field of a flapping foil. The main advantage of our approach is that the flow fields are time and space resolved and can be obtained time-efficiently. The foil is driven by a flapping mechanism that is optimized for studying both fish swimming and insect flight inside and outside the behavioral envelope. The mechanism generates sinusoidal heave and pitch kinematics, pre-described by the non-dimensional heave amplitude (0-6), the pitch amplitude (0° - 90°), the phase difference between pitch and heave (0° - 360°), and the dimensionless wavelength of the foil (3-18). We obtained this wide range of wavelengths for a foil 4 mm long by minimizing the soap film speed (0.25 m s- 1) and maximizing the flapping frequency range (4-25 Hz). The Reynolds number of the foil is of order 1,000 throughout this range. The resulting setup enables an effective assessment of vortex wake topology as a function of flapping kinematics. The efficiency of the method is further improved by carefully eliminating background noise in the visualization (e.g., reflections of the mechanism). This is done by placing mirrors at an angle behind the translucent film such that the camera views the much more distant and out-of-focus reflections of the black laboratory wall. The resulting high-quality flow visualizations require minimal image processing for flow interpretation. Finally, we demonstrate the

Effects of the foil flatness on irradiation performance of U10Mo monolithic mini-plates

DOE PAGES

Ozaltun, Hakan; Medvedev, Pavel G.; Rabin, Barry H.

2015-09-03

Monolithic plate-type fuels comprise of a high density, low enrichment, U10Mo fuel foil encapsulated in a cladding material. This concept generates several fabrication challenges such as flatness, centering or thickness variation. There are concerns, if these parameters have implications on overall performance. To investigate these inquiries, the effects of the foil flatness were studied. For this, a representative plate was simulated for an ideal case. The simulations were repeated for additional cases with various foil curvatures to evaluate the effects on the irradiation performance. The results revealed that the stresses and strains induced by fabrication process are not affected bymore » the flatness of the foil. Furthermore, fabrication stresses in the foil are relieved relatively fast in the reactor. The effects of the foil flatness on peak irradiation stressstrains are minimal. There is a slight increase in temperature for the case with maximum curvature. The major impact is on the displacement characteristics. Furthermore, while the case with a flat foil produces a symmetrical swelling, if the foil is curved, more swelling occurs on the thin-cladding side and the plate bows during irradiation.« less

Real-time simulator for designing electron dual scattering foil systems.

PubMed

Carver, Robert L; Hogstrom, Kenneth R; Price, Michael J; LeBlanc, Justin D; Pitcher, Garrett M

2014-11-08

The purpose of this work was to develop a user friendly, accurate, real-time com- puter simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator allows for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator also is a powerful educational tool. The simulator consists of an analytical algorithm for calculating electron fluence and X-ray dose and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with the reduced Gaussian formalism for scattering powers. The simulator also estimates central-axis and off-axis X-ray dose arising from the dual foil system. Once the geometry of the accelerator is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scat- tering foil material and Gaussian shape (thickness and sigma), and beam energy. The off-axis electron relative fluence or total dose profile and central-axis X-ray dose contamination are computed and displayed in real time. The simulator was validated by comparison of off-axis electron relative fluence and X-ray percent dose profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV, using present foils on an Elekta radiotherapy accelerator, the simulator was able to reproduce MC profiles to within 2% out to 20 cm from the central axis. The central-axis X-ray percent dose predictions matched measured data to within 0.5%. The calculation time was approximately 100 ms using a single Intel 2.93 GHz processor, which allows for real-time variation of foil geometrical parameters using slider bars. This work demonstrates how the user-friendly GUI and real-time nature of the simulator make it an effective educational tool for gaining a better understanding of the effects that various system

Collisions of plastic and foam laser-driven foils studied by orthogonal x-ray imaging.

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Metzler, N.; Karasik, M.; Serlin, V.; Obenschain, S. P.; Schmitt, A. J.; Velikovich, A. L.; Zalesak, S. T.; Gardner, J. H.; Weaver, J.; Oh, J.; Harding, E. C.

2007-11-01

We report an experimental study of hydrodynamic Rayleigh-Taylor and Richtmyer-Meshkov-type instabilities developing at the material interface produced in double-foil collisions. Our double-foil targets consist of a plastic foil irradiated by the 4 ns Nike KrF laser pulse at ˜50 TW/cm^2 and accelerated toward a stationary plastic or foam foil. Either the rear side of the front foil or the front side of the rear foil is rippled. Orthogonal imaging, i. e., a simultaneous side-on and face-on x-ray radiography of the targets has been used in these experiments to observe the process of collision and the evolution of the areal mass amplitude modulation. Its observed evolution is similar to the case of the classical RM instability in finite thickness targets first studied by Y. Aglitsky et al., Phys. Plasmas 13, 80703 (2006). Our data are favorably compared with 1D and 2D simulation results.

Foil cooling for rep-rated electron beam pumped KrF lasers

NASA Astrophysics Data System (ADS)

Giuliani, J. L.; Hegeler, F.; Sethian, J. D.; Wolford, M. F.; Myers, M. C.; Abdel-Khalik, S.; Sadowski, D.; Schoonover, K.; Novak, V.

2006-06-01

In rep-rated electron beam pumped lasers the foil separating the vacuum diode from the laser gas is subject to repeated heating due to partial beam stopping. Three cooling methods are examined for the Electra KrF laser at the Naval Research Laboratory (NRL). Foil temperature measurements for convective cooling by the recirculating laser gas and by spray mist cooling are reported, along with estimates for thermal conductive foil cooling to the hibachi ribs. Issues on the application of each of these approaches to laser drivers in a fusion power plant are noted. Work supported by DOE/NNSA.

Spectroscopic Measurements of Planar Foil Plasmas Driven by a MA LTD

NASA Astrophysics Data System (ADS)

Patel, Sonal; Yager-Elorriaga, David; Steiner, Adam; Jordan, Nick; Gilgenbach, Ronald; Lau, Y. Y.

2014-10-01

Planar foil ablation experiments are being conducted on the Linear Transformer Driver (LTD) at the University of Michigan. The experiment consists of a 400 nm-thick, Al planar foil and a current return post. An optical fiber is placed perpendicular to the magnetic field and linear polarizers are used to isolate the pi and sigma lines. The LTD is charged to +/-70 kV with approximately 400-500 kA passing through the foil. Laser shadowgraphy has previously imaged the plasma and measured anisotropy in the Magneto Rayleigh-Taylor (MRT) instability. Localized magnetic field measurements using Zeeman splitting during the current rise is expected to yield some insight into this anisotropy. Initial experiments use Na D lines of Al foils seeded with sodium to measure Zeeman splitting. Several ion lines are also currently being studied, such as Al III and C IV, to probe the higher temperature core plasma. In planned experiments, several lens-coupled optical fibers will be placed across the foil, and local magnetic field measurements will be taken to measure current division within the plasma. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant DGE 1256260.

Infrared particle detection for battery electrode foils

NASA Astrophysics Data System (ADS)

Just, P.; Ebert, L.; Echelmeyer, T.; Roscher, M. A.

2013-11-01

Failures of electrochemical cells caused by internal shorts still are an important issue to be faced by the cell manufacturers and their customers. A major cause for internal shorts are contaminated electrode foils. These contaminations have to be detected securely via a non-destructive inspection technique integrated into the electrode manufacturing process. While optical detection already is state of the art, infrared detection of particles finds a new field of application in the battery electrode manufacturing process. This work presents two approaches focusing on electrode inspection by electromagnetic radiation (visible and infrared). Copper foils with a carbon based coating were intentionally contaminated by slivers of aluminum and copper as well as by abraded coating particles. Optical excitation by a flash and a luminescent lamp was applied at different angles in order to detect the reflected visible radiation. A laser impulse was used to heat up the specimen for infrared inspection. Both approaches resulted in setups providing a high contrast between contaminations and the coated electrode foil. It is shown that infrared detection offers a higher security thanks to its reliance on absorbance and emissivity instead of reflectivity as it is used for optical detection. Infrared Detection offers a potential since it is hardly influenced by the particle's shape and orientation and the electrode's waviness.

Laser shock microforming of aluminum foil with fs laser

NASA Astrophysics Data System (ADS)

Ye, Yunxia; Feng, Yayun; Xuan, Ting; Hua, Xijun; Hua, Yinqun

2014-12-01

Laser shock microforming of Aluminum(Al) foil through fs laser has been researched in this paper. The influences of confining layer, clamping method and impact times on induced dent depths were investigated experimentally. Microstructure of fs laser shock forming Al foil was observed through Transmission electron microscopy (TEM). Under the condition of tightly clamping, the dent depths increase with impact times and finally tend to saturating. Another new confining layer, the main component of which is polypropylene, was applied and the confining effect of it is better because of its higher impedance. TEM results show that dislocation is one of the main deformation mechanisms of fs laser shock forming Al foil. Specially, most of dislocations exist in the form of short and discrete dislocation lines. Parallel straight dislocation slip line also were observed. We analyzed that these unique dislocation arrangements are due to fs laser-induced ultra high strain rate.

The adsorption properties of short chain alcohols and Triton X-100 mixtures at the water-air interface.

PubMed

Zdziennicka, Anna

2009-07-15

The adsorption behaviour at the water-air interface of aqueous solutions of Triton X-100 and methanol (ethanol) mixtures at constant Triton X-100 (TX-100) concentration equal to 10(-7), 10(-6), 10(-5), 10(-4), 6x10(-4) and 10(-3)M, respectively, in a wide range of alcohol concentration was investigated by surface tension measurements of solutions. The obtained values of the surface tension of aqueous solutions of "pure" methanol and ethanol and their mixtures with TX-100, as well as the values of propanol solutions and their mixtures with TX-100 as a function of alcohol concentration taken from the literature were compared with those calculated from the Szyszkowski, Connors and Fainerman and Miller equations. On the basis of this comparison it was stated that these equations can be useful for description of the solution surface tension in the wide range of alcohol concentration, but only at the concentrations of Triton X-100 corresponding to its unsaturated layer in the absence of alcohol. It was also stated that the Connors equation is more adequate for concentrated aqueous organic solutions. The measured values of the surface tension were used in the Gibbs equation to determine the surface excess concentration of Triton X-100 and alcohol. Next, on the basis of Gibbs adsorption isotherms those of Guggenheim and Adam and real adsorption isotherms were established. From the obtained adsorption isotherms it results that alcohol influences the shape of TX-100 isotherms in the whole range of alcohol and TX-100 concentration, but TX-100 influences the alcohol isotherms only at TX-100 concentration at which the saturated monolayer at the solution-air interface is formed in the absence of alcohol. This conclusion was confirmed by analysis of the composition of the surface layer in comparison to the composition of the bulk phase in the equilibrium state.

Rayleigh-Taylor instability of two-specie laser-accelerated foils

NASA Astrophysics Data System (ADS)

Ratliff, T. H.; Yi, S. A.; Khudik, V.; Yu, T. P.; Pukhov, A.; Chen, M.; Shvets, G.

2010-11-01

When an ultra intense circularly polarized laser pulse irradiates an ultra thin film, a monoenergetic ion beam is produced with characteristics well suited for applications in science and medicine. Upon laser incidence, the electrons in the foil are pushed via the ponderomotive force to the foil rear; the charge separation field then accelerates ions. In the accelerating frame the ions are trapped in a potential well formed by the electrostatic and inertial forces. However, their energy spectrum can be quickly degraded by the Rayleigh-Taylor (RT) instability. Stabilization in the case of a two-specie foil is the subject of this poster. First, we use a 1D particle-in-cell (PIC) simulation to establish an equilibrium state of the two-specie foil in the accelerating frame. Next we perturb this equilibrium and analytically investigate the 2D RT instability. Analytical results are compared with 2-D simulations. We also investigate parametrically various effects on the RT growth rate. The protons completely separate from the carbons, and although the vacuum-carbon interface remains unstable, the large spatial extent of the carbon layer prevents perturbations from feeding through to the proton layer. The monoenergetic proton beam is shown to persist beyond the conclusion of the laser pulse interaction. [1] T.P. Yu, A. Pukhov, G. Shvets, and M Chen, Phys. Rev. Lett. (in press)

CCC Observations of Pluto, Neptune and Triton with the San Fernando automatic meridian circle.

NASA Astrophysics Data System (ADS)

Muiños, J. L.; Belizón, F.; Vallejo, M.; Mallamaci, C. C.; Pérez, J. A.; Marmolejo, L. F.; Navarro, J. L.; Sedeño, J. A.

2003-11-01

The San Fernando automatic meridian circle (CMASF) is a meridian telescope built by Grubb-Parsons in 1948 fully automated between 1987 and 1995. In 1996 was moved from the Real Instituto y Observatorio de la Armada (ROA) in San Fernando to the Carlos U. Cesco (CUC) mountain observatory in San Juan (Argentine). The CUC is owned by the Observatorio Astronómico Félix Aguilar (OAFA) of National University of San Juan. In 1999 the telescope was provided with a CCD camera borrowed by the Copenhagen University Observatory (CUO). Between March and October of 2001 a campaign of observations of Pluto, Neptune and its satellite Triton was carried out with the CMASF. They were observed every five days while their transits through the CUC meridian happened during the night. In total 12 transits of Pluto, 15 of Neptune and 16 of Triton were got during that period. In this paper we present the results of the campaign.

Slumped glass foils as substrate for adjustable x-ray optics

NASA Astrophysics Data System (ADS)

Salmaso, Bianca; Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Pelliciari, Carlo; Spiga, Daniele; Vecchi, Gabriele; Pareschi, Giovanni

2016-09-01

Thin glass modular mirrors are a viable solution to build future X-ray telescopes with high angular resolution and large collecting area. In our laboratories, we shape thin glass foils by hot slumping and we apply pressure to assist the replication of a cylindrical mould figure; this technology is coupled with an integration process able to damp low frequency errors and produces optics in the Wolter I configuration, typical for the X-ray telescopes. From the point of view of the hot slumping process, the efforts were focused in reducing low-, mid- and high- frequency errors of the formed Eagle glass foils. Some of our slumped glass foils were used for the development of active X-ray optics, where piezoelectric actuators are used to correct the slumped glass foil deviations from the ideal shape. In particular, they were used for the Adjustable X-raY optics for astrOnoMy project (AXYOM) developed in Italy, and the X-ray Surveyor mission, as developed at the Smithsonian Astrophysical Observatory / Center for Astrophysics (SAO/CfA) in USA. In this paper we describe the optimisation of the hot slumping process, comparing the results with the requirements of the considered active optics projects. Finally, since the present configuration of the Pennsylvania State University (PSU) coating equipment is limited to 100 x 100 mm2, the slumped glass foils used for the SAO project were cut from 200 x 200 mm2 to 100 x 100 mm2, and a low-frequency change was observed. A characterisation of the profile change upon cutting is presented.

Alpha Oscillations during Incidental Encoding Predict Subsequent Memory for New "Foil" Information.

PubMed

Vogelsang, David A; Gruber, Matthias; Bergström, Zara M; Ranganath, Charan; Simons, Jon S

2018-05-01

People can employ adaptive strategies to increase the likelihood that previously encoded information will be successfully retrieved. One such strategy is to constrain retrieval toward relevant information by reimplementing the neurocognitive processes that were engaged during encoding. Using EEG, we examined the temporal dynamics with which constraining retrieval toward semantic versus nonsemantic information affects the processing of new "foil" information encountered during a memory test. Time-frequency analysis of EEG data acquired during an initial study phase revealed that semantic compared with nonsemantic processing was associated with alpha decreases in a left frontal electrode cluster from around 600 msec after stimulus onset. Successful encoding of semantic versus nonsemantic foils during a subsequent memory test was related to decreases in alpha oscillatory activity in the same left frontal electrode cluster, which emerged relatively late in the trial at around 1000-1600 msec after stimulus onset. Across participants, left frontal alpha power elicited by semantic processing during the study phase correlated significantly with left frontal alpha power associated with semantic foil encoding during the memory test. Furthermore, larger left frontal alpha power decreases elicited by semantic foil encoding during the memory test predicted better subsequent semantic foil recognition in an additional surprise foil memory test, although this effect did not reach significance. These findings indicate that constraining retrieval toward semantic information involves reimplementing semantic encoding operations that are mediated by alpha oscillations and that such reimplementation occurs at a late stage of memory retrieval, perhaps reflecting additional monitoring processes.

Viewpoint: Central adjudication of myocardial infarction in outcome-driven clinical trials--common patterns in TRITON, RECORD, and PLATO?

PubMed

Serebruany, Victor L; Atar, Dan

2012-09-01

Central adjudication in randomised controlled outcome-driven trials represents a traditional approach to maintain data integrity by applying uniformed rules for assessment of clinical events. It was the purpose of this investigation to determine the patterns of myocardial infarction (MI) adjudication in the TRITON, RECORD, and PLATO trials. We were matching centrally-adjudicated MI's (CAMI's) from the official trial publication with the site-reported MI (SRMI's) count from the Food and Drug Administration's secondary analyses for the investigational compounds prasugrel (TRITON), rosiglitazone (RECORD), and ticagrelor (PLATO). CAMI numbers showed a remarkable discrepancy to SRMI's by more than a doubling of the difference: from 72 to 145 events in TRITON favoring prasugrel (from a hazard ratio [HR]=0.76, p=0.08; to a HR=0.76, p<0.001), and from 44 to 89 events in favour of ticagrelor in PLATO (from a HR=0.94, p=0.095; to a HR=0.84, p<0.001). In contrast, in the RECORD trial, the CAMI count was less than the SRMI count (from 24 to 8 events, from a HR=1.42, p=0.93; to a HR=1.14, p=0.96), in this case diminishing cardiovascular hazards in favour of rosiglitazone. In conclusion, central adjudication in the TRITON, the RECORD, and the PLATO trial turned out to have a critical impact on study outcomes. Trial publications should in the future include site-reported major efficacy and safety endpoints to preserve data integrity. The regulatory authorities should consider independent audits when there is a major disagreement between centrally adjudicated and site reported events influencing the results of a major clinical trial.

Structural stiffness and Coulomb damping in compliant foil journal bearings: Theoretical considerations

NASA Astrophysics Data System (ADS)

Ku, C.-P. Roger; Heshmat, Hooshang

1994-07-01

Compliant foil bearings operate on either gas or liquid, which makes them very attractive for use in extreme environments such as in high-temperature aircraft turbine engines and cryogenic turbopumps. However, a lack of analytical models to predict the dynamic characteristics of foil bearings forces the bearing designer to rely on prototype testing, which is time-consuming and expensive. In this paper, the authors present a theoretical model to predict the structural stiffness and damping coefficients of the bump foil strip in a journal bearing or damper. Stiffness is calculated based on the perturbation of the journal center with respect to its static equilibrium position. The equivalent viscous damping coefficients are determined based on the area of a closed hysteresis loop of the journal center motion. The authors found, theoretically, that the energy dissipated from this loop was mostly contributed by the frictional motion between contact surfaces. In addition, the source and mechanism of the nonlinear behavior of the bump foil strips were examined. With the introduction of this enhanced model, the analytical tools are now available for the design of compliant foil bearings.

Large transient nonproton ion movements in purple membrane suspensions are abolished by solubilization in Triton X-100.

PubMed Central

Marinetti, T; Mauzerall, D

1986-01-01

Light-induced release/uptake of both protons and other ions cause transient changes in conductivity in suspensions of purple membrane (PM) fragments (Marinetti, Tim, and David Mauzerall, 1983, Proc. Natl. Acad. Sci. USA, 80:178-180). We find that the release/uptake of nonproton ions with quantum yield greater than 1 is observed at most pHs and ionic strengths. Only at both low pH and low ionic strength is the conductivity transient mostly due to protons. Our hypothesis is that during the photocycle, changes occur in the PM's dense surface charge distribution that result in changes in the number of counterions bound or condensed at the membrane surface. To test this, the PM structure was perturbed with the nonionic detergent Triton X-100. Immediately after addition, Triton does not abolish the nonproton ion movements; in fact at low detergent concentrations (0.02% vol/vol) the signal amplitudes increased considerably. However, when PM is completely solubilized into monomers in Triton, the conductivity transients are due to protons alone, though at lower quantum yield compared with native PM. These results suggest that changes in the surface charge distribution in native PM's photocycle could contribute to proton transfer between the aqueous phase and bR itself. PMID:3019444

Novel technique of making thin target foil of high density material via rolling method

NASA Astrophysics Data System (ADS)

Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

2018-05-01

The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R F; Bailey, J E; Cuneo, M E

We report the development of techniques to diagnose plasmas produced by X-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW X-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated 3-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments in which 1 cm, 180 eV tungsten pinches photoionized foils composed of 200{angstrom} Fe and 300{angstrom} NaF co-mixed and sandwiched between 1000{angstrom} layers of Lexan (CHO), and discuss the application of this work to benchmarking astrophysical models.« less

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R. F.; Bailey, J. E.; Cuneo, M. E.

We report the development of techniques to diagnose plasmas produced by x-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW x-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated three-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments using 1-cm, 180-eV tungsten pinches to photoionize foils made of 200 Aa Fe and 300 Aa NaF co-mixed and sandwiched between 1000 Aa layers of Lexan (C16H14O3), and discuss the application of this work to benchmarking astrophysical models.« less

Diagnostic performances of clinical laboratory tests using Triton X-100 to reduce the biohazard associated with routine testing of Ebola virus-infected patients.

PubMed

Tempestilli, Massimo; Pucci, Luigia; Notari, Stefania; Di Caro, Antonino; Castilletti, Concetta; Rivelli, Maria Rosaria; Agrati, Chiara; Pucillo, Leopoldo Paolo

2015-11-01

Ebola virus, an enveloped virus, is the cause of the largest and most complex Ebola virus disease (EVD) outbreak in West Africa. Blood or body fluids of an infected person may represent a biohazard to laboratory workers. Laboratory tests of virus containing specimens should be conducted in referral centres at biosafety level 4, but based on the severity of clinical symptoms, basic laboratories might be required to execute urgent tests for patients suspected of EVD. The aim of this work was to compare the analytical performances of laboratory tests when Triton X-100, a chemical agent able to inactivate other enveloped viruses, was added to specimens. Results of clinical chemistry, coagulation and haematology parameters on samples before and after the addition of 0.1% (final concentration) of Triton X-100 and 1 h of incubation at room temperature were compared. Overall, results showed very good agreement by all statistical analyses. Triton X-100 at 0.1% did not significantly affect the results for the majority of the analytes tested. Triton X-100 at 0.1% can be used to reduce the biohazard in performing laboratory tests on samples from patients with EVD without affecting clinical decisions.

Solid methane on Triton and Pluto - 3- to 4-micron spectrophotometry

NASA Technical Reports Server (NTRS)

Spencer, John R.; Buie, Marc W.; Bjoraker, Gordon L.

1990-01-01

Methane has been identified in the Pluto/Charon system on the basis of absorption features in the reflectance spectrum at 1.5 and 2.3 microns; attention is presently given to observations of a 3.25 micron-centered deep absorption feature in Triton and Pluto/Charon system reflectance spectra. This absorption may indicate the presence of solid methane, constituting either the dominant surface species or a mixture with a highly transparent substance, such as N2 frost.

Approximating the near-edge mass absorption coefficients for Ni using an ultra-thin bimetal foil

DOE PAGES

Alkire, Randall W.

2016-11-01

In an effort to improve the characteristics of a fluorescing metal-foil-based beam position monitor, a new bimetal ultra-thin (0.98/0.67 µm) Ti–Ni foil was introduced to replace an existing single-element ultra-thin 0.5 µm thick Cr foil. During characterization it was determined that absorption measurements on the bimetal foil could be used to fit the Ni mass absorption coefficients accurately in the vicinity of the NiKedge. Comparison with experimental results from the literature demonstrated that the fitting procedure produced coefficients with uncertainties of the order of ±1%. Once determined, these fit coefficients allowed the thickness of an independently mounted 8 µm thickmore » Ni foil to be computed from absorption measurements instead of relying on a tool-based measurement of the foil thickness. Using the 8 µm thick foil, a continuous map of Ni mass absorption coefficients was produced at 1 eV resolution throughout the near-edge region. Lastly, this high-resolution map marks a significant improvement over the existing NIST XCOM or FFAST database mass absorption coefficients, which have estimated errors of 10–20% for the near-edge region.« less

Dynamic interference of two anti-phase flapping foils in side-by-side arrangement in an incompressible flow

NASA Astrophysics Data System (ADS)

Bao, Y.; Zhou, D.; Tao, J. J.; Peng, Z.; Zhu, H. B.; Sun, Z. L.; Tong, H. L.

2017-03-01

A two-dimensional computational hydrodynamic model is developed to investigate the propulsive performance of a flapping foil system in viscous incompressible flows, which consists of two anti-phase flapping foils in side-by-side arrangement. In the simulations, the gap between the two foils is varied from 1.0 to 4.0 times of the diameter of the semi-circular leading edge; the amplitude-based Strouhal number is changed from 0.06 to 0.55. The simulations therefore cover the flow regimes from negligible to strong interference in the wake flow. The generations of drag and thrust are investigated as well. The numerical results reveal that the counter-phase flapping motion significantly changes the hydrodynamic force generation and associated propulsive wake. Furthermore, the wake interference becomes important for the case with a smaller foil-foil gap and induces the inverted Bénard von Kármán vortex streets. The results show that the hydrodynamic performance of two anti-phase flapping foils can be significantly different from an isolated pitching foil. Findings of this study are expected to provide new insight for developing hydrodynamic propulsive systems by improving the performance based on the foil-foil interaction.

Flapping foil power generator performance enhanced with a spring-connected tail

NASA Astrophysics Data System (ADS)

Liu, Zhengliang; Tian, Fang-Bao; Young, John; Lai, Joseph C. S.

2017-12-01

The flexibility effects on the performance of a flapping foil power generator are numerically studied by using the immersed boundary-lattice Boltzmann method at a Reynolds number of 1100. The flapping foil system consists of a rigid NACA0015 foil undergoing harmonic pitch and plunge motions and a passively actuated flat plate pinned to the trailing edge of the rigid foil. The flexibility is modeled by a torsional spring model at the conjuncture of the rigid foil and the tail. Here, a parametric study on mass density and natural frequency is conducted under the optimum kinematic condition of the rigid system identified from the literature and numerical simulations made for reduced frequency f* = 0.04-0.24 and pitch amplitude θ0 = 40°-90°. Four typical cases are discussed in detail by considering time histories of hydrodynamic loads and tail deformations under the optimal and non-optimal kinematic conditions. Results show that under the rigid-system optimal kinematic condition, a tail with appropriate mass density (μ = 0.60) and resonant frequency ( fr*=1.18 ) can improve the maximum efficiency by 7.24% accompanied by an increase of 6.63% in power compared to those of a rigid foil with a rigid tail. This is because the deflection of the tail reduces the low pressure region on the pressure surface (i.e., the lower surface during the upstroke or the upper surface during the downstroke) caused by the leading edge vortex after the stroke reversal, resulting in a higher efficiency. At high flapping frequencies, a spring-connected tail ( fr*=0.13 ) eliminates the large spike in the moment observed in high stiffness cases, reducing the power required for the pitch motion, resulting in 117% improvement in efficiency over that with a rigid tail at a reduced frequency of 0.24.

Lenz's Law with Aluminum Foil and a Lengthwise Slit

ERIC Educational Resources Information Center

Berls, Rob; Ruiz, Michael J.

2018-01-01

The classic demonstration illustrating Lenz's law by dropping a magnet through a copper pipe is presented using household aluminum foil right out of the box. Then comes the surprise. The teacher presents an aluminum foil cylinder with a missing lengthwise slice (cut before class). Will the demonstration still work? Students are amazed at the…

Prediction and characterization of heat-affected zone formation due to neighboring nickel-aluminum multilayer foil reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, David P.; Hirschfeld, Deidre A.; Hooper, Ryan J.

2015-09-01

Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. Much of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To enhance the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purposemore » of evaluating new foil-substrate combinations for screening and optimization. The model is experimentally validated using a commercially available Ni-Al multilayer foils and different alloys.« less

Application study on aircraft structures of CFRP laminates with embedded SMA foils

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Takeda, Nobuo

2002-07-01

This paper reports some research results for the application study of the smart materials an structural using Shape Memory Alloy (SMA) foils. First, the authors acquired the recovery strain of CFRP laminates generated by the recovery stress of the pre-strained SMA foils. Then, the quasi-static load-unload tests were conducted using several kinds of quasi-isotropic CFRP laminates with embedded SMA foils. Micro-mechanics of damage behavior due to the effects of the recovery strain and the first transverse crack strain were discussed. The improvement of maximum 40 percent for the onset strain of the transverse cracks and maximum 60 percent for the onset strain of delamination were achieved for CFRP laminates with embedded pre-strained SMA foils compared with standard CFRP laminates. Furthermore, the authors conducted the structural element test for application to actual structures. Testing technique and the manufacturing technique of the structural element specimen were established.

Flapping propulsion with side-by-side pitching foils

NASA Astrophysics Data System (ADS)

Huera-Huarte, Francisco

2016-11-01

Fish schools are one of the most common types of collective behaviour observed in nature. One of the reasons why fish swim in groups, is to reduce the cost of transport of the school. In this work we explore the propulsive performance of two foils flapping in a symmetric configuration, i.e. with an out-of-phase flapping motion. Direct thrust measurements and Particle Image Velocimetry (PIV) allowed a detailed examination of the forces and the wake generated by the system, for different kinematics (swept angles and frequencies) and shaft separations. For certain specific cases, volumetric PIV shows major differences on how the different structures in the wake of the system evolve, depending on the imposed kinematics and the side-by-side separation between the foils. Results obtained will be compared against data produced with isolated flapping foils with similar imposed kinematics, with the aim to better understand the interactions between both and the performance of the system as a whole. The author would like to acknowledge the financial support provided by the Spanish Ministerio de Economia y competitividad (MINECO) through Grant DPI2015-71645-P.

Investigations on electroluminescent tapes and foils in relation to their applications in automotive

NASA Astrophysics Data System (ADS)

Plotog, Ioan

2015-02-01

The electroluminescent (EL) tapes or foils having barrier films for an additional level of protection against the toughest environments conditions, offer a large area of applications. The EL lights, due to their characteristics, began to be used not only in the entertainment industry, but also for automotive and aerospace applications. In the paper, the investigations regarding EL foils technical performances in relation to their applications as light sources in automotive ambient light were presented. The experiments were designed based on the results of EL foils electrical properties previous investigations done in laboratory conditions, taking into account the range of automotive ambient temperatures for sinusoidal alternative supply voltage. The measurements for different temperatures were done by keeping the EL foils into electronic controlled oven that ensures the dark enclosure offering conditions to use a lux-meter in order to measure and maintain under control light emission intensity. The experiments results define the EL foils characteristics as load in automotive ambient temperatures condition, assuring so the data for optimal design of a dedicated inverter.

Selecting lineup foils in eyewitness identification experiments: experimental control and real-world simulation.

PubMed

Clark, S E; Tunnicliff, J L

2001-06-01

Experimental research on eyewitness identification follows a standard principle of experimental design. Perpetrator-present and perpetrator-absent lineups are constructed with the same foils, so that the two conditions are identical except for the presence or absence ofthe trueperpetrator ofthe crime. However, this aspect of the design simulates conditions that do not correspond to those of real criminal investigations. Specifically, these conditions can create perp-absent lineups in which the foils are selected based on their similarity to an unknown person--the real perpetrator. Analysis of the similarity relations predicts that when foils for perp-absent lineups are selected based on their match to the perpetrator the false identification rate will be lower than if the foils are selected based on their match to the innocent suspect. This prediction was confirmed in an experiment that compared these two perp-absent lineup conditions. These results suggest that false identification rates in previous experiments would have been higher if the foils had been selected based on their match to the innocent suspect, rather than the absent perpetrator.

Analysis of Hybrid Type Boron-Doped Carbon Stripper Foils in J-PARC RCS

NASA Astrophysics Data System (ADS)

Yamazaki, Y.; Yoshimoto, M.; Takeda, O.; Kinsho, M.; Taguchi, T.; Yamamoto, S.; Kurihara, T.; Sugai, I.

2013-03-01

J-PARC (Japan-Proton Accelerator Research Complex) requires a carbon stripper foil to strip electrons from the H- beam supplied by the linac before injection into the Rapid Cycling Synchrotron (RCS) [1]. The foil thickness is about μm (200μg/cm2) corresponding to conversion efficiency of 99.7% from the primary H- beams of 181MeV energy to H+. We have successfully developed the Hybrid type thick Boron-doped Carbon (HBC) stripper foil, which showed a drastic improvement the lifetime without thickness reduction and shrinkage at the irradiated area. We started to study carbon stripper foils microscopically why carbon foils have considerable endurance for the beam impact by boron-doped. At first step, we made a comparison of ion irradiation effect between normal carbon and HBC by the electric microscope, ion-induced analysis. In particular, it seems that grain size of boron-rich area became much larger by irradiation for HBC. It was also observed that the boron-rich grain grew up by taking around material and generated pinholes more than 100 nm near itself consequently.

Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

NASA Astrophysics Data System (ADS)

Fan, Qiwen; Du, Yinghui; Zhang, Rong; Xu, Guoji

2013-04-01

Thin diamond-like carbon (DLC) stripper foils ˜5 μg/cm2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ˜4 μg/cm2 in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine-saccharose as releasing agent, which were previously covered with evaporated carbon layers ˜1 μg/cm2 in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4for the 197Au- (˜9 MeV, ˜1 μA) and 63Cu- (˜9 MeV, ˜1 μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (ID/IG) measured by the Raman spectroscopy is0.78.

X-ray optics made from thin plastic foils

NASA Astrophysics Data System (ADS)

Schnopper, Herbert W.; Silver, Eric H.; Ingram, Russell H.; Christensen, Finn E.; Hussain, Ahsen M.; Barbera, Marco; Romaine, Suzanne E.; Collura, Alfonso; Kenter, Almus T.; Bandler, Simon; Murray, Stephen S.

1999-09-01

New design concepts and materials can be used to produce very lightweight, thin foil approximations, to Wolter I and other x-ray optics. Structures are designed around a central hub and spacers that connect one spoked wheels. Figure defining, thin pins span the distance between the wheels. Thin, metal coated or multilayered, plastic foils can be formed into cones, cylinders or spirals for x-ray telescopes or lenses. Imaging and spectroscopic data obtained with x- ray lenses are presented and they indicate that a 60 cm diameter, 4.65 m focal length x-ray telescope can have a half power diameter of < 2 arcmin.

Acceleration of planar foils by the indirect-direct drive scheme

NASA Astrophysics Data System (ADS)

Honrubia, J. J.; Martínez-Val, J. M.; Bocher, J. L.; Faucheux, G.

1996-05-01

We have investigated the hydrodynamic response of plastic and aluminum foils accelerated by a pulse formed by an x-ray prepulse followed by the main laser pulse. This illumination scheme, so-called indirect-direct drive scheme, has been proposed as an alternative to the direct and indirect drive. The advantages of such a scheme are that it can contribute to solve the problem of uniformity of the direct drive and, at the same time, it can be much more efficient and use simpler targets than the indirect-drive. Experiments about this hybrid drive scheme have been performed at Limeil with the PHEBUS facility and the standard experimental set-up and diagnostics. The agreement between experiments and simulations is good for quantities such as the energy of the laser converted into x-rays and the burnthrough time of the converter foil. To simulate the full hydrodynamic evolution of the converter and target foils separated a distance of 1 mm, 2-D effects should be taken into account. The basic goals have been to check the simulation codes developed by the Institute of Nuclear Fusion and to determine the hydrodynamic response of the target foil to the hybrid pulse. These goals have been fulfilled.

Comparative study of the interaction of CHAPS and Triton X-100 with the erythrocyte membrane.

PubMed

Rodi, P M; Bocco Gianello, M D; Corregido, M C; Gennaro, A M

2014-03-01

The zwitterionic detergent CHAPS, a derivative of the bile salts, is widely used in membrane protein solubilization. It is a "facial" detergent, having a hydrophilic side and a hydrophobic back. The objective of this work is to characterize the interaction of CHAPS with a cell membrane. To this aim, erythrocytes were incubated with a wide range of detergent concentrations in order to determine CHAPS partition behavior, and its effects on membrane lipid order, hemolytic effects, and the solubilization of membrane phospholipids and cholesterol. The results were compared with those obtained with the nonionic detergent Triton X-100. It was found that CHAPS has a low affinity for the erythrocyte membrane (partition coefficient K=0.06mM(-1)), and at sub-hemolytic concentrations it causes little effect on membrane lipid order. CHAPS hemolysis and phospholipid solubilization are closely correlated. On the other side, binding of Triton X-100 disorders the membrane at all levels, and has independent mechanisms for hemolysis and solubilization. Differential behavior was observed in the solubilization of phospholipids and cholesterol. Thus, the detergent resistant membranes (DRM) obtained with the two detergents will have different composition. The behaviors of the two detergents are related to the differences in their molecular structures, suggesting that CHAPS does not penetrate the lipid bilayer but binds in a flat position on the erythrocyte surface, both in intact and cholesterol depleted erythrocytes. A relevant result for Triton X-100 is that hemolysis is not directly correlated with the solubilization of membrane lipids, as it is usually assumed. Copyright © 2013 Elsevier B.V. All rights reserved.

Applications of beam-foil spectroscopy to atomic collisions in solids

NASA Technical Reports Server (NTRS)

Sellin, I. A.

1976-01-01

Some selected papers presented at the Fourth International Conference on Beam-Foil Spectroscopy, whose results are of particular pertinence to ionic collision phenomena in solids, are reviewed. The topics discussed include solid target effects and means of surmounting them in the measurement of excited projectile ion lifetimes for low-energy heavy element ions; the electron emission accompanying the passage of heavy particles through solid targets; the collision broadening of X rays emitted from 100 keV ions moving in solids; residual K-shell excitation in chlorine ions penetrating carbon; comparison between 40 MeV Si on gaseous SiH4 targets at 300 mtorr and 40 MeV Si on Al; and the emergent surface interaction in beam-foil spectroscopy. A distinct overlap of interests between the sciences of beam-foil spectroscopy and atomic collisions in solids is pointed out.

Uniaxial creep property and viscoelastic-plastic modelling of ethylene tetrafluoroethylene (ETFE) foil

NASA Astrophysics Data System (ADS)

Li, Yintang; Wu, Minger

2015-02-01

Ethylene tetrafluoroethylene (ETFE) foil has been widely used in spatial structures for its light weight and high transparency. This paper studies short- and long-term creep properties of ETFE foil. Two series of short-term creep and recovery tests were performed, in which residual strain was observed. A long-term creep test of ETFE foil was also conducted and lasted about 400 days. A viscoelastic-plastic model was then established to describe short-term creep and recovery behaviour of ETFE foil. This model contains a traditional generalised Kelvin part and an added steady-flow component to represent viscoelastic and viscoplastic behaviour, respectively. The model can fit tests' data well at three stresses and six temperatures. Additionally, time-temperature superposition was adopted to simulate long-term creep behaviour of ETFE foil. Horizontal shifting factors were determined by W.L.F. equation in which transition temperature was simulated by shifting factors. Using this equation, long-term creep behaviours at three temperatures were predicted. The results of the long-term creep test showed that a short-term creep test at identical temperatures was insufficient to predict additional creep behaviour, and the long-term creep test verified horizontal shifting factors which were derived from the time-temperature superposition.

Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

DOEpatents

Engelhaupt, Darell E.

1981-09-22

The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.

LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammon, Duncan L.; Clarke, Kester D.; Alexander, David J.

2015-05-29

The cleaning, canning, rolling and final trimming of Low Enriched Uranium-10 wt. pct. Molybdenum (LEU-10Mo) foils for ATR (Advanced Test Reactor) fuel plates to be used in the AFIP-7 (ATR Full Size Plate In Center Flux Trap Position) experiments are summarized. Six Zr-clad foils were produced from two LEU-10Mo castings supplied to Los Alamos National Laboratory (LANL) by Y-12 National Security Complex. Details of cleaning and canning procedures are provided. Hot- and cold-rolling results are presented, including rolling schedules, images of foils in-process, metallography and local compositions of regions of interest, and details of final foil dimensions and process yield.more » This report was compiled from the slides for the presentation of the same name given by Duncan Hammon on May 12, 2011 at the AFIP-7 Lessons Learned meeting in Salt Lake City, UT, with Los Alamos National Laboratory document number LA-UR 11-02898.« less

Method of using deuterium-cluster foils for an intense pulsed neutron source

DOEpatents

Miley, George H.; Yang, Xiaoling

2013-09-03

A method is provided for producing neutrons, comprising: providing a converter foil comprising deuterium clusters; focusing a laser on the foil with power and energy sufficient to cause deuteron ions to separate from the foil; and striking a surface of a target with the deuteron ions from the converter foil with energy sufficient to cause neutron production by a reaction selected from the group consisting of D-D fusion, D-T fusion, D-metal nuclear spallation, and p-metal. A further method is provided for assembling a plurality of target assemblies for a target injector to be used in the previously mentioned manner. A further method is provided for producing neutrons, comprising: splitting a laser beam into a first beam and a second beam; striking a first surface of a target with the first beam, and an opposite second surface of the target with the second beam with energy sufficient to cause neutron production.

SU-E-T-25: Real Time Simulator for Designing Electron Dual Scattering Foil Systems.

PubMed

Carver, R; Hogstrom, K; Price, M; Leblanc, J; Harris, G

2012-06-01

To create a user friendly, accurate, real time computer simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator should allow for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator consists of an analytical algorithm for calculating electron fluence and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with a refined Moliere formalism for scattering powers. The simulator also estimates central-axis x-ray dose contamination from the dual foil system. Once the geometry of the beamline is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scattering foil material and Gaussian shape (thickness and sigma), and beam energy. The beam profile and x-ray contamination are displayed in real time. The simulator was tuned by comparison of off-axis electron fluence profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV and using present foils on the Elekta radiotherapy accelerator, the simulator profiles agreed to within 2% of MC profiles from within 20 cm of the central axis. The x-ray contamination predictions matched measured data to within 0.6%. The calculation time was approximately 100 ms using a single processor, which allows for real-time variation of foil parameters using sliding bars. A real time dual scattering foil system simulator has been developed. The tool has been useful in a project to redesign an electron dual scattering foil system for one of our radiotherapy accelerators. The simulator has also been useful as an instructional tool for our medical physics graduate students. © 2012 American Association of Physicists in Medicine.

Thermal Sensitive Foils in Physics Experiments

ERIC Educational Resources Information Center

Bochnícek, Zdenek; Konecný, Pavel

2014-01-01

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Colorimetric detection of melamine in milk based on Triton X-100 modified gold nanoparticles and its paper-based application

NASA Astrophysics Data System (ADS)

Gao, Nan; Huang, Pengcheng; Wu, Fangying

2018-03-01

In this study, we have developed a method for rapid, highly efficient and selective detection of melamine. The negatively charged citrate ions form an electrostatic layer on gold nanoparticles (AuNPs) and keep the NPs dispersed and stable. When citrate-capped AuNPs were further modified with Triton X-100, it stabilized the AuNPs against the conditions of high ionic strength and a broad pH range. However, the addition of melamine caused the destabilization and aggregation of NPs. This may be attributed to the interaction between melamine and the AuNPs through the ligand exchange with citrate ions on the surface of AuNPs leading Triton X-100 to be removed. As a result, the AuNPs were unstable, resulting in the aggregation. The aggregation induced a wine red-to-blue color change, and a new absorption peak around 630 nm appeared. Triton X-100-AuNPs could selectively detect melamine at the concentration as low as 5.1 nM. This probe was successfully applied to detect melamine in milk. Furthermore, paper-based quantitative detection system using this colorimetric probe was also demonstrated by integrating with a smartphone.

Numerical and experimental studies of hydrodynamics of flapping foils

NASA Astrophysics Data System (ADS)

Zhou, Kai; Liu, Jun-kao; Chen, Wei-shan

2018-04-01

The flapping foil based on bionics is a sort of simplified models which imitate the motion of wings or fins of fish or birds. In this paper, a universal kinematic model with three degrees of freedom is adopted and the motion parallel to the flow direction is considered. The force coefficients, the torque coefficient, and the flow field characteristics are extracted and analyzed. Then the propulsive efficiency is calculated. The influence of the motion parameters on the hydrodynamic performance of the bionic foil is studied. The results show that the motion parameters play important roles in the hydrodynamic performance of the flapping foil. To validate the reliability of the numerical method used in this paper, an experiment platform is designed and verification experiments are carried out. Through the comparison, it is found that the numerical results compare well with the experimental results, to show that the adopted numerical method is reliable. The results of this paper provide a theoretical reference for the design of underwater vehicles based on the flapping propulsion.

Propulsive performance of pitching foils with variable chordwise flexibility

NASA Astrophysics Data System (ADS)

Zeyghami, Samane; Moored, Keith; Lehigh University Team

2017-11-01

Many swimming and flying animals propel themselves efficiently through water by oscillating flexible fins. These fins are not homogeneously flexible, but instead their flexural stiffness varies along their chord and span. Here we seek to evaluate the effect stiffness profile on the propulsive performance of pitching foils. Stiffness profile characterizes the variation in the local fin stiffness along the chord. To this aim, we developed a low order model of a functionally-graded material where the chordwise flexibility is modeled by two torsional springs along the chordline and the stiffness and location of the springs can be varied arbitrarily. The torsional spring structural model is then strongly coupled to a boundary element fluid model to simulate the fluid-structure interactions. Keeping the leading edge kinematics unchanged, we alter the stiffness profile of the foil and allow it to swim freely in response to the resulting hydrodynamic forces. We then detail the dependency of the hydrodynamic performance and the wake structure to the variations in the local structural properties of the foil.

Molecular basis of interactions between mitochondrial proteins and hydroxyapatite in the presence of Triton X-100, as revealed by proteomic and recombinant techniques.

PubMed

Yamamoto, Takenori; Tamaki, Haruna; Katsuda, Chie; Nakatani, Kiwami; Terauchi, Satsuki; Terada, Hiroshi; Shinohara, Yasuo

2013-08-02

Hydroxyapatite chromatography is a very important step in the purification of voltage-dependent anion channels (VDACs) and several members of solute carrier family 25 (Slc25) from isolated mitochondria. In the presence of Triton X-100, VDACs and Slc25 members present a peculiar property, i.e., a lack of interaction with hydroxyapatite, resulting in their presence in the flow-through fraction of hydroxyapatite chromatography. This property has allowed selective isolation of VDACs and Slc25 members from a mixture of total mitochondrial proteins. However, the reason why only these few proteins are selectively obtained in the presence of Triton X-100 from the flow-though fraction of hydroxyapatite chromatography has not yet been adequately understood. In this study, when we examined the protein species in the flow-through fractions by proteomic analysis, VDAC isoforms, Slc25 members, and some other membrane proteins were identified. All the mitochondrial proteins had in common high hydrophobicity over their entire protein sequences. When the proteins were fused to soluble proteins, the fused proteins showed affinity for hydroxyapatite even in the presence of Triton X-100. Based on these results, we discussed the molecular basis of the interactions between proteins and hydroxyapatite in the presence of Triton X-100. Copyright © 2013 Elsevier B.V. All rights reserved.

Proteome analysis of the triton-insoluble erythrocyte membrane skeleton.

PubMed

Basu, Avik; Harper, Sandra; Pesciotta, Esther N; Speicher, Kaye D; Chakrabarti, Abhijit; Speicher, David W

2015-10-14

Erythrocyte shape and membrane integrity is imparted by the membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact erythrocytes, indicating isolation of essentially intact membrane skeletons. These erythrocyte "Triton Skeletons" have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized membrane skeleton proteins and their associated membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in erythrocyte membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the membrane skeleton should lead to new insights into erythrocyte membrane biology and pathogenic mutations that perturb membrane stability. Biological significance Current models of erythrocyte membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the erythrocyte membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the membrane that contain these proteins should yield novel insights into how the membrane skeleton

Neutron sensitivity of 6Li-based suspended foil microstrip neutron detectors using Schott Borofloat® 33 microstrip electrodes

NASA Astrophysics Data System (ADS)

Edwards, Nathaniel S.; Montag, Benjamin W.; Henson, Luke C.; Bellinger, Steven L.; Nichols, Daniel M.; Reichenberger, Michael A.; Fronk, Ryan G.; McGregor, Douglas S.

2018-06-01

6Li foils, each 75-μm thick, were positioned between a Schott Borofloat® 33 microstrip electrode and a planar drift electrode to construct suspended foil microstrip neutron detectors. MCNP6 simulations of two detector configurations, one containing a single 6Li foil and the other containing five 6Li foils, indicated expected maximum intrinsic thermal-neutron detection efficiencies of 18.36% and 54.08%, respectively. For comparison, the intrinsic thermal-neutron detection efficiency as a function of thermal-neutron beam position along the foil span was experimentally measured for both detector configurations. A non-uniform intrinsic thermal-neutron detection efficiency distribution was observed along the span of the 6Li foil(s) between the microstrip and drift electrodes. Maximum intrinsic thermal-neutron detection efficiencies of 12.58 ± 0.15% and 29.75 ± 0.26% for the single and five 6Li foils were measured, respectively. Gamma-ray rejection ratios of 6.46 × 10-5 ± 4.32 × 10-7 and 7.96 × 10-5 ± 4.65 × 10-7 were also measured, respectively, for a 137Cs exposure rate of 50 mR h-1. All measurements were conducted with the 6Li foil(s) contained within a sealed aluminum enclosure pressurized with 10 psig of P-10 gas.

Method and apparatus for tensile testing of metal foil

NASA Technical Reports Server (NTRS)

Wade, O. W. (Inventor)

1976-01-01

A method for obtaining accurate and reproducible results in the tensile testing of metal foils in tensile testing machines is described. Before the test specimen are placed in the machine, foil side edges are worked until they are parallel and flaw free. The specimen are also aligned between and secured to grip end members. An aligning apparatus employed in the method is comprised of an alignment box with a longitudinal bottom wall and two upright side walls, first and second removable grip end members at each end of the box, and a means for securing the grip end members within the box.

Simulation of turn-by-turn passage of protons through the H-minus stripping foil in booster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardner, C.

Equations for transverse emittance growth due to multiple passes of circulating proton beam through the H-minus stripping foil in Booster were developed in [1]. These were based on simple principles of statistics and simple assumptions about the initial distribution of particles incident on the foil. It was assumed there that the foil dimensions and position of the incoming beam are such that all particles hit the foil on every turn around the machine. In the present note we assume only that all incoming H-minus ions from Linac hit the foil and are stripped of their electrons. The resulting protons circulatemore » indefinitely around the machine. Setups in which the foil width is reduced so that not all protons hit the foil on every turn are studied here by simulation. The aim is to determine the effectiveness of such setups in reducing the emittance growth of circulating proton beam during the injection of H-minus beam. The simulations also serve as a check of the equations developed in [1], and vice versa. The particulars of the simulation setup are given in Sections 1 through 11. Figures 1 through 12 show simulation results for the case in which all particles hit the foil on every turn. The results are in good agreement with those obtained from the equations of reference [1]. Figures 13 through 19 show simulation results for various setups in which the foil width is reduced. These results are summarized in Section 12. In all gures the horizontal axis gives the turn number. The unit of the vertical axis is micrometers ( m) in all plots of emittance.« less

Foil Panel Mirrors for Nonimaging Applications

NASA Technical Reports Server (NTRS)

Kuyper, D. J.; Castillo, A. A.

1984-01-01

Large durable, lightweight mirrors made by bonding thick aluminum foil to honeycomb panels or other rigid, flat backings. Mirrors suitable for use as infrared shields, telescope doors, solar-furnance doors, advertising displays, or other reflectors that require low thermal emissivity and high specularity but do not require precise surface figure necessary for imaging.

The possibility of using platinum foils with a rippled surface as diffraction gratings

NASA Astrophysics Data System (ADS)

Korsukov, V. E.; Ankudinov, A. V.; Butenko, P. N.; Knyazev, S. A.; Korsukova, M. M.; Obidov, B. A.; Shcherbakov, I. P.

2014-09-01

The atomic structure and surface relief of thin cold-rolled platinum foils upon recrystallization annealing and loading under ultrahigh vacuum conditions have been studied by low energy electron diffraction (LEED), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). The surface of samples upon high-temperature annealing and subsequent uniaxial extension of recrystallized Pt foils represents a fractal structure of unidirectional ripples on various spatial scales. The total fractal dimension of this surface is D GW = 2.3, while the fractal dimensions along and across ripples are D ‖ ≈ 1 and D ⊥ ≈ 1.3, respectively. The optical spectra of a halogen lamp and a PRK-2 mercury lamp were recorded using these rippled Pt foils as reflection diffraction gratings. It is shown that Pt foils with this surface relief can be used as reflection diffraction gratings for electromagnetic radiation in a broad spectral range.

High-performance lithium-ion batteries with 1.5 μm thin copper nanowire foil as a current collector

NASA Astrophysics Data System (ADS)

Chu, Hsun-Chen; Tuan, Hsing-Yu

2017-04-01

Cu Foil, a thin sheet of Cu, is the common anode current collector in commercial lithium ion batteries (LIBs) which accounts for ∼ 10 wt% of the total cell weight. However, thickness reduction of LIB-based Cu foils below 6 μm has been limited by the incapability of conventional rolling annealing or electrodeposition process. We here report a new type of Cu foil, so called Cu nanowire foil (CuNW foil), for use as an LIB anode current collector. We fabricate Cu NW foils by rolling press Cu nanowire fabric to reduce the thickness down to ∼1.5 μm with an areal weight down to ∼1.2 mg cm-2 and a density approximately 96% to that of bulk Cu. The rough surface and porous structure of CuNW foil enable better wetting and adhering properties of graphite slurry on foil. In full cell examination, a cell of a areal capacity of 3 mAh cm-2 exhibits 83.6% capacity retention for 600 cycles at 0.6 C that meets the standard specification of most commercial LIBs. As a proof-of-concept of demonstration, we fabricate a 700 mA pouch-type battery implemented with graphite-Cu NWs foil anodes to serve as energy supply to operate electronic devices.

Patterning of Thick Parylene Films by Oxygen Plasma for Application as Exploding Foil Initiator Flyer Material

DTIC Science & Technology

2009-09-01

exploding foil initiator ( EFI ) type fuzes are being explored to...Acronyms Au gold Cr chromium Cu copper EFI exploding foil initiator BOE buffered oxide etch MEMS microelectromechanical systems RIE reactive ion...Patterning of Thick Parylene Films by Oxygen Plasma for Application as Exploding Foil Initiator Flyer Material by Eugene Zakar and Michael

Superconducting characteristics in purified tantalum-foils

NASA Astrophysics Data System (ADS)

Hu, Qinghua; Wang, Zhihe

2018-07-01

We have conducted extensive investigations on the electrical transport and magnetization on a purified tantalum foil with extremely sharp resistive transition (transition width ΔTc < 0.02 K) at 0 T and residual resistivity ratio ρ290K/ρ5K= 16.75. Many effects, such as anisotropic field-induced resistive broadening and second peak of the magnetization-hysteresis loop, are observed in the sample. The maximum upper critical field determined by criteria of R/Rn = 0.9 is about 1.08 T rather weak compared to that in cuprate and/or iron-based superconductors. Although the value of upper critical field Hc2(0) and the field dependence of effective pinning energy U show that the flux pinning potential is weaker, the critical current density Jc(2 K, 0 T) = 1.145 × 105 A/cm2 and the effect of second peak indicate that there should be higher collective vortex pinning potential in the tantalum foil. The carriers are dominated by holes with the density n = 6.6 × 1022/cm3.

Influence of UV and Gamma radiations on the induced birefringence of stretched poly(vinyl) alcohol foils

NASA Astrophysics Data System (ADS)

Nechifor, Cristina-Delia; Zelinschi, Carmen Beatrice; Dorohoi, Dana-Ortansa

2014-03-01

The aim of our paper is to evidence the influence of Gamma and UV radiations on the induced birefringence of poly(vinyl alcohol) stretched foils. Thin foils of PVA were prepared and dried without modifying their surfaces. The polymeric foils were irradiated from 15 min to 6 h using UV and Gamma radiations. The induced by stretching under heating birefringence of PVA films was measured at λ = 589.3 nm with a Babinet Compensator. Physico-chemical processes (photo stabilization, photo degradation, oxidation) induced by irradiation of polymer matrix influence both the stretching degree and the anisotropy of etired foils. An increase of birefringence versus the stretching ratio of the PVA foils was evidenced for all studied samples. The dependence of the birefringence on the exposure time, stretching ratio and nature of radiation was also confirmed.

Applying a foil queue micro-electrode in micro-EDM to fabricate a 3D micro-structure

NASA Astrophysics Data System (ADS)

Xu, Bin; Guo, Kang; Wu, Xiao-yu; Lei, Jian-guo; Liang, Xiong; Guo, Deng-ji; Ma, Jiang; Cheng, Rong

2018-05-01

Applying a 3D micro-electrode in a micro electrical discharge machining (micro-EDM) can fabricate a 3D micro-structure with an up and down reciprocating method. However, this processing method has some shortcomings, such as a low success rate and a complex process for fabrication of 3D micro-electrodes. By focusing on these shortcomings, this paper proposed a novel 3D micro-EDM process based on the foil queue micro-electrode. Firstly, a 3D micro-electrode was discretized into several foil micro-electrodes and these foil micro-electrodes constituted a foil queue micro-electrode. Then, based on the planned process path, foil micro-electrodes were applied in micro-EDM sequentially and the micro-EDM results of each foil micro-electrode were able to superimpose the 3D micro-structure. However, the step effect will occur on the 3D micro-structure surface, which has an adverse effect on the 3D micro-structure. To tackle this problem, this paper proposes to reduce this adverse effect by rounded corner wear at the end of the foil micro-electrode and studies the impact of machining parameters on rounded corner wear and the step effect on the micro-structure surface. Finally, using a wire cutting voltage of 80 V, a current of 0.5 A and a pulse width modulation ratio of 1:4, the foil queue micro-electrode was fabricated by wire electrical discharge machining. Also, using a pulse width of 100 ns, a pulse interval of 200 ns, a voltage of 100 V and workpiece material of 304# stainless steel, the foil queue micro-electrode was applied in micro-EDM for processing of a 3D micro-structure with hemispherical features, which verified the feasibility of this process.

Simultaneous schlieren photography and soot foil in the study of detonation phenomena

NASA Astrophysics Data System (ADS)

Kellenberger, Mark; Ciccarelli, Gaby

2017-10-01

The use of schlieren photography has been essential in unravelling the complex nature of high-speed combustion phenomena, but its line-of-sight integration makes it difficult to decisively determine the nature of multi-dimensional combustion wave propagation. Conventional schlieren alone makes it impossible to determine in what plane across the channel an observed structure may exist. To overcome this, a technique of simultaneous high-speed schlieren photography and soot foils was demonstrated that can be applied to the study of detonation phenomena. Using a kerosene lamp, soot was deposited on a glass substrate resulting in a semi-transparent sheet through which schlieren source light could pass. In order to demonstrate the technique, experiments were carried out in mixtures of stoichiometric hydrogen-oxygen at initial pressures between 10 and 15 kPa. Compared to schlieren imaging obtained without a sooted foil, high-speed video results show schlieren images with a small reduction of contrast with density gradients remaining clear. Areas of high temperature cause soot lofted from the foil to incandescence strongly, resulting in the ability to track hot spots and flame location. Post-processing adjustments were demonstrated to make up for camera sensitivity limitations to enable viewing of schlieren density gradients. High-resolution glass soot foils were produced that enable direct coupling of schlieren video to triple-point trajectories seen on the soot foils, allowing for the study of three-dimensional propagation mechanisms of detonation waves.

A New Analysis Tool Assessment for Rotordynamic Modeling of Gas Foil Bearings

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; SanAndres, Luis

2010-01-01

Gas foil bearings offer several advantages over traditional bearing types that make them attractive for use in high-speed turbomachinery. They can operate at very high temperatures, require no lubrication supply (oil pumps, seals, etc.), exhibit very long life with no maintenance, and once operating airborne, have very low power loss. The use of gas foil bearings in high-speed turbomachinery has been accelerating in recent years, although the pace has been slow. One of the contributing factors to the slow growth has been a lack of analysis tools, benchmarked to measurements, to predict gas foil bearing behavior in rotating machinery. To address this shortcoming, NASA Glenn Research Center (GRC) has supported the development of analytical tools to predict gas foil bearing performance. One of the codes has the capability to predict rotordynamic coefficients, power loss, film thickness, structural deformation, and more. The current paper presents an assessment of the predictive capability of the code, named XLGFBTH (Texas A&M University). A test rig at GRC is used as a simulated case study to compare rotordynamic analysis using output from the code to actual rotor response as measured in the test rig. The test rig rotor is supported on two gas foil journal bearings manufactured at GRC, with all pertinent geometry disclosed. The resulting comparison shows that the rotordynamic coefficients calculated using XLGFBTH represent the dynamics of the system reasonably well, especially as they pertain to predicting critical speeds.

The Chevron Foil Thrust Bearing: Improved Performance Through Passive Thermal Management and Effective Lubricant Mixing

NASA Technical Reports Server (NTRS)

Bruckner, Robert

2013-01-01

An improved foil thrust bearing is described that eliminates or reduces the need for forced cooling of the bearing foils while at the same time improves the load capacity of the bearing, enhances damping, provides overload tolerance, and eliminates the high speed load capacity drop-off that plagues the current state of the art. The performance improvement demonstrated by the chevron foil thrust bearing stems from a novel trailing edge shape that splays the hot lubricant in the thin film radially, thus preventing hot lubricant carry-over into the ensuing bearing sector. Additionally, the chevron shaped trailing edge induces vortical mixing of the hot lubricant with the gas that is naturally resident within the inter-pad region of a foil thrust bearing. The elimination of hot gas carry-over in combination with the enhanced mixing has enabled a completely passive thermally managed foil bearing design. Laboratory testing at NASA has confirmed the original analysis and reduced this concept to practice.

Composite metal foil and ceramic fabric materials

DOEpatents

Webb, B.J.; Antoniak, Z.I.; Prater, J.T.; DeSteese, J.G.

1992-03-24

The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed. 11 figs.

Experimental study of the spatial distributions of relativistic electron beams reflected and refracted by a thin foil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serov, A. V., E-mail: serov@x4u.lebedev.ru; Mamonov, I. A.

2016-08-15

Photographs of cross sections of an electron beam scattered from thin foils have been obtained on a dosimetric film. The procession of images makes it possible to obtain the spatial distribution of particles both reflected from a foil and passed through it. The spatial distribution of electrons incident on aluminum, copper, and lead foils, as well as on bimetallic foils composed of aluminum and lead layers and of aluminum and copper layers, has been measured. The effect of the material and thickness of the foil, as well as of the angle between the initial beam trajectory and the target plane,more » on the spatial distribution of electrons has been studied. The effect of the sequence of the metal layers in bimetallic foils on the distribution of beams has been analyzed. A 7.4-MeV microtron has been used as a source of electrons.« less

Effects of the foil flatness on the stress-strain characteristics of U10Mo alloy based monolithic mini-plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hakan Ozaltun; Pavel Medvedev

The effects of the foil flatness on stress-strain behavior of monolithic fuel mini-plates during fabrication and irradiation were studied. Monolithic plate-type fuels are a new fuel form being developed for research and test reactors to achieve higher uranium densities. This concept facilitates the use of low-enriched uranium fuel in the reactor. These fuel elements are comprised of a high density, low enrichment, U–Mo alloy based fuel foil encapsulated in a cladding material made of Aluminum. To evaluate the effects of the foil flatness on the stress-strain behavior of the plates during fabrication, irradiation and shutdown stages, a representative plate frommore » RERTR-12 experiments (Plate L1P756) was considered. Both fabrication and irradiation processes of the plate were simulated by using actual irradiation parameters. The simulations were repeated for various foil curvatures to observe the effects of the foil flatness on the peak stress and strain magnitudes of the fuel elements. Results of fabrication simulations revealed that the flatness of the foil does not have a considerable impact on the post fabrication stress-strain fields. Furthermore, the irradiation simulations indicated that any post-fabrication stresses in the foil would be relieved relatively fast in the reactor. While, the perfectly flat foil provided the slightly better mechanical performance, overall difference between the flat-foil case and curved-foil case was not significant. Even though the peak stresses are less affected, the foil curvature has several implications on the strain magnitudes in the cladding. It was observed that with an increasing foil curvature, there is a slight increase in the cladding strains.« less

Large-area thin self-supporting carbon foils with MgO coatings

NASA Astrophysics Data System (ADS)

Stolarz, Anna; Maier-Komor, Peter

2002-03-01

Large area self-supporting carbon foils in the thickness of range of 8-22 μg/cm 2, coated with approximately 4 μg/cm 2 MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm 2. Problems related to the parting agent preparation, floating procedure, and mounting onto frames are discussed. Special precautions necessary to avoid damage during foil drying, storage and transportation are suggested.

High Temperature Performance Evaluation of a Compliant Foil Seal

NASA Technical Reports Server (NTRS)

Salehi, Mohsen; Heshmat, Hooshang; Walton, James F., II

2001-01-01

The key points to be gleaned from the effort reported herein are that the CFS (Compliant Foil Seal) has been demonstrated in conjunction with a foil bearing in a small gas turbine simulator at temperatures as high as 1000 F and outperformed a comparable brush seal. Having demonstrated the feasibility of the CFS, it would appear that this new seal design has application potential in a wide range of machines. What remains is to demonstrate performance at higher pressure ratios, consistent performance at large rotor excursions and the ability to manufacture the seal in much larger sizes exceeding by an order of magnitude that which has been tested to date.

Role of target material in proton acceleration from thin foils irradiated by ultrashort laser pulses.

PubMed

Tayyab, M; Bagchi, S; Ramakrishna, B; Mandal, T; Upadhyay, A; Ramis, R; Chakera, J A; Naik, P A; Gupta, P D

2014-08-01

We report on the proton acceleration studies from thin metallic foils of varying atomic number (Z) and thicknesses, investigated using a 45 fs, 10 TW Ti:sapphire laser system. An optimum foil thickness was observed for efficient proton acceleration for our laser conditions, dictated by the laser ASE prepulse and hot electron propagation behavior inside the material. The hydrodynamic simulations for ASE prepulse support the experimental observation. The observed maximum proton energy at different thicknesses for a given element is in good agreement with the reported scaling laws. The results with foils of different atomic number Z suggest that a judicious choice of the foil material can enhance the proton acceleration efficiency, resulting into higher proton energy.

X-ray optics made from thin plastic foils

NASA Astrophysics Data System (ADS)

Schnopper, H. W.; Barbera, M.; Ingram, R.; Silver, E.; Romaine, S.; Bandler, S.; Murray, S.; Christensen, F. E.; Hussain, A.; Collura, A.

2000-10-01

New design concepts and materials can be used to produce lightweight, thin foil approximations, to Wolter I and other X-ray optics. Structures are designed around a central hub and spacers that connect two (or three) spoked wheels. Figure defining, thin pins span the distance between the wheels. Thin, metal coated or multilayered, plastic foils can be formed into full cones, cylinders or spirals for X-ray telescopes or lenses. High resolution X-ray scattering data were obtained for single foils at Cu K (8 KeV). Multi-energy (0.28 - 8 KeV) data were obtained with a multichannel plate imager in a 17 m beam line with a point-to-point focusing, cylindrical X-ray lens with 14 shells. The largest shell has a diameter of 175 mm and a length of 100 mm. Typical images have a FWHM of 20 arcsec. The results indicate that a 60 cm diameter, 4.65 m focal length X-ray telescope can have an HPD of considerably less than 2 arcmin. This research is supported, in part by NASA Grant NAG5-5268, ONR Grant N00014-95-1-1248, and by institutional funding from the Smithsonian Astrophysical Observatory. The SAO multilayer facility receives support from NASA Grant NAG5-5095. This work made use of the MRSEC Shared Experimental Facilities at MIT supported by NSF Grant DMR94-00334.

Titanium conversion coatings on the aluminum foil AA 8021 used for lithium-ion battery package

NASA Astrophysics Data System (ADS)

Xia, Xu-Feng; Gu, Ying-Ying; Xu, Shi-Ai

2017-10-01

In this study, an environment-friendly titanium (Ti) conversion coating was successfully deposited on the aluminum foil AA 8021 in the solution containing hexafluorotitanic acid (H2TiF6), and its morphology, composition, growth process, hydrophilicity and corrosion resistance were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray photoelectric spectroscopy (XPS), contact-angle measurements (CAM) and salt spray exposure. The peeling strength between the Ti treated Al foil and the modified polypropylene (PP) film (PP grafted with maleic anhydride, PP-g-MAH) (Al/PP-g-MAH) was measured by T-peeling test. The results show that the Ti conversion coating is a multi-component coating composed primarily of metal oxides (TiO2 and Al2O3) and metal fluoride (AlF3). Ti treated Al foil shows better corrosion resistance than untreated and alkali-cleaned Al foils. The peeling strength of PP-g-MAH film with Ti treated Al foils is approximately 30 times higher than that with untreated Al foils. Thus, Ti treatment is a promising approach to improve the corrosion resistance and peeling strength of aluminum/polymer composite film (Al/P) used in the lithium-ion battery package.

A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

2002-01-01

Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

Metal foil method for noncontact measurement of lateral vibrations of a nonmetallic cylinder by a solenoid

NASA Astrophysics Data System (ADS)

Han, Soon Woo; Bang, Young Bong; Kim, Yoon Young

2006-10-01

This investigation shows that if a solenoid encircles a metal foil loop wound around a nonmetallic cylinder vibrating laterally, an electromotive force is induced in the solenoid. The induction is possible only when the foil loop is complete and an antisymmetric magnetic field is applied to the foil. In this work, stationary permanent magnets were used. Because the solenoid is the sensing element, no physical contact between the element and a test specimen is required. The effects of the metal foil thickness and width on the measurement sensitivity were studied and vibration modal testing of an acryl cylinder was performed.

Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

ERIC Educational Resources Information Center

Planinsic, Gorazd; Gojkosek, Mihael

2011-01-01

Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

Hypolipidemic activity of Phellinus rimosus against triton WR-1339 and high cholesterol diet induced hyperlipidemic rats.

PubMed

Rony, K A; Ajith, T A; Nima, N; Janardhanan, K K

2014-03-01

Patients with the risk for atherosclerotic disease will be targeted to reduce the existing hyperlipidemia. The hypolipidemic activity of Phellinus rimosus was studied using triton WR-1339 and high cholesterol diet (HCD) induced models. The triton induced elevated lipid profile was attenuated by P. rimosus or standard drug atorvastatin. Similarly, administration of P. rimosus along with HCD significantly decline serum triglyceride, total cholesterol, low-density lipoprotein, with elevating the high-density lipoprotein. Thiobarbituric acid reacting substances in heart and liver significantly decreased; where as activity of enzymatic antioxidants and level of reduced glutathione were significantly increased. In both models, P. rimosus extract showed a significant ameliorative effect on the elevated atherogenic index as well as LDL/HDL-C ratio. The hypolipidemic activity of P. rimosus can be ascribed to its inhibitory effect on the liver HMG CoA reductase activity. The results suggest the possible therapeutic potential of this fungus as hypolipidemic agent. Copyright © 2014 Elsevier B.V. All rights reserved.

Design of a medium size x-ray mirror module based on thin glass foils

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Pareschi, Giovanni

2016-07-01

The hot slumping glass technology for X-ray mirror is under development and in the last years the results have been improved. Nustar is the first X-ray telescope based on slumped glass foils and it benefit is the low cost compared to the direct polishing of glass. With the slumping technique it is possible to maintain the glass mass to low values with respect to the direct polishing, but in general the angular resolution is worst. A further technique based on glass is the cold shaping of foils. The improved capabilities of manufacturing thin glass foils, pushed by the industrial application for screens, open new possibilities for X-ray mirror. The increase in strength of thin tempered glasses, the reduction of thickness errors and the good roughness of flat foils are potentially great advantages. In this paper a design of a mediumsize X-ray mirror module is analysed. It is based on integration of glass foils, stacked directly on a supporting structure that is part of the X-ray telescope using stiffening ribs as spacer between foils. The alignment of each stack is performed directly into the integration machine avoiding the necessity of the alignment of different stacked modules. A typical module (glass optic and metallic structure) provides an effective area of 10 cm2/kg at 1 keV (with a mass of about 50- 100 kg and a focal length of 10 m).

First experience with carbon stripping foils for the 160 MeV H- injection into the CERN PSB

NASA Astrophysics Data System (ADS)

Weterings, Wim; Bracco, Chiara; Jorat, Louise; Noulibos, Remy; van Trappen, Pieter

2018-05-01

160 MeV H- beam will be delivered from the new CERN linear accelerator (Linac4) to the Proton Synchrotron Booster (PSB), using a H- charge-exchange injection system. A 200 µg/cm2 carbon stripping foil will convert H- into protons by stripping off the electrons. The H- charge-exchange injection principle will be used for the first time in the CERN accelerator complex and involves many challenges. In order to gain experience with the foil changing mechanism and the very fragile foils, in 2016, prior to the installation in the PSB, a stripping foil test stand has been installed in the Linac4 transfer line. In addition, parts of the future PSB injection equipment are also temporarily installed in the Linac4 transfer line for tests with a 160 MeV H- commissioning proton beam. This paper describes the foil changing mechanism and control system, summarizes the practical experience of gluing and handling these foils and reports on the first results with beam.

An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.

2010-01-01

Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

Flow over a traveling wavy foil with a passively flapping flat plate

NASA Astrophysics Data System (ADS)

Liu, Nansheng; Peng, Yan; Liang, Youwen; Lu, Xiyun

2012-05-01

Flow over a traveling wavy foil with a passively flapping flat plate has been investigated using a multiblock lattice Boltzmann equation and the immersed boundary method. The foil undergoes prescribed undulations in the lateral direction and the rigid flat plate has passive motion determined by the fluid structure interaction. This simplified model is used to study the effect of the fish caudal fin and its flexibility on the locomotion of swimming animals. The flexibility of the caudal fin is modeled by a torsion spring acting about the pivot at the conjuncture of the wavy foil and the flat plate. The study reveals that the passively oscillating flat plate contributes half of the propulsive force. The flexibility, represented by the nondimensional natural frequency F, plays a very important role in the movement and propulsive force generation of the whole body. When the plate is too flexible, the drag force is observed. As the flat plate becomes more rigid, the propulsive force that is generated when the undulation is confined to last part of the wavy foil becomes larger. The steady movement occurs at F=5. These results are consistent with the observations of some swimming animals in nature.

Experimental and Theoretical Study on Minimum Achievable Foil Thickness during Asymmetric Rolling

PubMed Central

Tang, Delin; Liu, Xianghua; Song, Meng; Yu, Hailiang

2014-01-01

Parts produced by microforming are becoming ever smaller. Similarly, the foils required in micro-machines are becoming ever thinner. The asymmetric rolling technique is capable of producing foils that are thinner than those produced by the conventional rolling technique. The difference between asymmetric rolling and conventional rolling is the ‘cross-shear’ zone. However, the influence of the cross-shear zone on the minimum achievable foil thickness during asymmetric rolling is still uncertain. In this paper, we report experiments designed to understand this critical influencing factor on the minimum achievable thickness in asymmetric rolling. Results showed that the minimum achievable thickness of rolled foils produced by asymmetric rolling with a rolling speed ratio of 1.3 can be reduced to about 30% of that possible by conventional rolling technique. Furthermore, the minimum achievable thickness during asymmetric rolling could be correlated to the cross-shear ratio, which, in turn, could be related to the rolling speed ratio. From the experimental results, a formula to calculate the minimum achievable thickness was established, considering the parameters cross-shear ratio, friction coefficient, work roll radius, etc. in asymmetric rolling. PMID:25203265

Viscous investigation of a flapping foil propulsor

NASA Astrophysics Data System (ADS)

Posri, Attapol; Phoemsapthawee, Surasak; Thaweewat, Nonthipat

2018-01-01

Inspired by how fishes propel themselves, a flapping-foil device is invented as an alternative propulsion system for ships and boats. The performance of such propulsor has been formerly investigated using a potential flow code. The simulation results have shown that the device has high propulsive efficiency over a wide range of operation. However, the potential flow gives good results only when flow separation is not present. In case of high flapping frequency, the flow separation can occur over a short instant due to fluid viscosity and high angle of attack. This may cause a reduction of propulsive efficiency. A commercial CFD code based on Lattice Boltzmann Method, XFlow, is then employed in order to investigate the viscous effect over the propulsive performance of the flapping foil. The viscous results agree well with the potential flow results, confirming the high efficiency of the propulsor. As expected, viscous results show lower efficiency in high flapping frequency zone.

Two-dimensional dosimetry of radiotherapeutical proton beams using thermoluminescence foils.

PubMed

Czopyk, L; Klosowski, M; Olko, P; Swakon, J; Waligorski, M P R; Kajdrowicz, T; Cuttone, G; Cirrone, G A P; Di Rosa, F

2007-01-01

In modern radiation therapy such as intensity modulated radiation therapy or proton therapy, one is able to cover the target volume with improved dose conformation and to spare surrounding tissue with help of modern measurement techniques. Novel thermoluminescence dosimetry (TLD) foils, developed from the hot-pressed mixture of LiF:Mg,Cu,P (MCP TL) powder and ethylene-tetrafluoroethylene (ETFE) copolymer, have been applied for 2-D dosimetry of radiotherapeutical proton beams at INFN Catania and IFJ Krakow. A TLD reader with 70 mm heating plate and CCD camera was used to read the 2-D emission pattern of irradiated foils. The absorbed dose profiles were evaluated, taking into account correction factors specific for TLD such as dose and energy response. TLD foils were applied for measuring of dose distributions within an eye phantom and compared with predictions obtained from the MCNPX code and Eclipse Ocular Proton Planning (Varian Medical Systems) clinical radiotherapy planning system. We demonstrate the possibility of measuring 2-D dose distributions with point resolution of about 0.5 x 0.5 mm(2).

Edge-on dislocation loop in anisotropic hcp zirconium thin foil

NASA Astrophysics Data System (ADS)

Wu, Wenwang; Xia, Re; Qian, Guian; Xu, Shucai; Zhang, Jinhuan

2015-10-01

Edge-on dislocation loops with 〈 a 〉 -type and 〈 c 〉 -type of Burgers vectors can be formed on prismatic or basel habit planes of hexagonal close-packed (hcp) zirconium alloys during in-situ ion irradiation and neutron irradiation experiments. In this work, an anisotropic image stress method was employed to analyze the free surface effects of dislocation loops within hcp Zr thin foils. Calculation results demonstrate that image stress has a remarkable effect on the distortion fields of dislocation loops within infinite medium, and the image energy becomes remarkable when dislocation loops are situated close to the free surfaces. Moreover, image forces of the 1 / 2 〈 0001 〉 (0001) dislocation loop within (0001) thin foil is much stronger than that of the 1 / 3 〈 11 2 bar 0 〉 (11 2 bar 0) dislocation loop within (11 2 bar 0) thin foil of identical geometrical configurations. Finally, image stress effect on the physical behaviors of loops during in-situ ion irradiation experiments is discussed.

Method for fabrication of ceramic dielectric films on copper foils

DOEpatents

Ma, Beihai; Narayanan, Manoj; Dorris, Stephen E.; Balachandran, Uthamalingam

2015-03-10

The present invention provides a method for fabricating a ceramic film on a copper foil. The method comprises applying a layer of a sol-gel composition onto a copper foil. The sol-gel composition comprises a precursor of a ceramic material suspended in 2-methoxyethanol. The layer of sol-gel is then dried at a temperature up to about 250.degree. C. The dried layer is then pyrolyzed at a temperature in the range of about 300 to about 450.degree. C. to form a ceramic film from the ceramic precursor. The ceramic film is then crystallized at a temperature in the range of about 600 to about 750.degree. C. The drying, pyrolyzing and crystallizing are performed under a flowing stream of an inert gas. In some embodiments an additional layer of the sol-gel composition is applied onto the ceramic film and the drying, pyrolyzing and crystallizing steps are repeated for the additional layer to build up a thicker ceramic layer on the copper foil. The process can be repeated one or more times if desired.

Structure and mechanical properties of foils made of nanocrystalline beryllium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhigalina, O. M., E-mail: zhigal@ns.crys.ras.ru; Semenov, A. A.; Zabrodin, A. V.

2016-07-15

The phase composition and structural features of (45–90)-μm-thick foils obtained from nanocrystalline beryllium during multistep thermomechanical treatment have been established using electron microscopy, electron diffraction, electron backscattering diffraction, and energy-dispersive analysis. This treatment is shown to lead to the formation of a structure with micrometer- and submicrometer-sized grains. The minimum average size of beryllium grains is 352 nm. The inclusions of beryllium oxide (BeO) of different modifications with tetragonal (sp. gr. P4{sub 2}/mnm) and hexagonal (sp. gr. P6{sub 3}/mmc) lattices are partly ground during deformation to a size smaller than 100 nm and are located along beryllium grain boundaries inmore » their volume, significantly hindering migration during treatment. The revealed structural features of foils with submicrometer-sized crystallites provide the thermal stability of their structural state. Beryllium with this structure is a promising material for X-ray instrument engineering and for the production of ultrathin (less than 10 μm) vacuum-dense foils with very high physicomechanical characteristics.« less

Copper foils with gradient structure in thickness direction and different roughnesses on two surfaces fabricated by double rolling

NASA Astrophysics Data System (ADS)

Wang, Xi-yong; Liu, Xue-feng; Zou, Wen-jiang; Xie, Jian-xin

2013-12-01

Copper foils with gradient structure in thickness direction and different roughnesses on two surfaces were fabricated by double rolling. The two surface morphologies of double-rolled copper foils are quite different, and the surface roughness values are 61 and 1095 nm, respectively. The roughness value of matt surface can meet the requirement for bonding the resin matrix with copper foils used for flexible printed circuit boards, thus may omit traditional roughening treatment; the microstructure of double-rolled copper foils demonstrates an obviously asymmetric gradient feature. From bright surface to matt surface in thickness direction, the average grain size first increases from 2.3 to 7.4 μm and then decreases to 3.6 μm; compared with conventional rolled copper foils, the double-rolled copper foils exhibit a remarkably increased bending fatigue life, and the increased range is about 16.2%.

Actinide Foil Production for MPACT Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beller, Denis

Sensitive fast-neutron detectors are required for use in lead slowing down spectrometry (LSDS), an active interrogation technique for used nuclear fuel assay for Materials Protection, Accounting, and Controls Technologies (MPACT). During the past several years UNLV sponsored a research project at RPI to investigate LSDS; began development of fission chamber detectors for use in LSDS experiments in collaboration with INL, LANL, and Oregon State U.; and participated in a LSDS experiment at LANL. In the LSDS technique, research has demonstrated that these fission chamber detectors must be sensitive to fission energy neutrons but insensitive to thermal-energy neutrons. Because most systemsmore » are highly sensitive to large thermal neutron populations due to the well-known large thermal cross section of 235U, even a miniscule amount of this isotope in a fission chamber will overwhelm the small population of higher-energy neutrons. Thus, fast-fission chamber detectors must be fabricated with highly depleted uranium (DU) or ultra-pure thorium (Th), which is about half as efficient as DU. Previous research conducted at RPI demonstrated that the required purity of DU for assay of used nuclear fuel using LSDS is less than 4 ppm 235U, material that until recently was not available in the U.S. In 2009 the PI purchased 3 grams of ultra-depleted uranium (uDU, 99.99998% 238U with just 0.2 ± 0.1 ppm 235U) from VNIIEF in Sarov, Russia. We received the material in the form of U3O8 powder in August of 2009, and verified its purity and depletion in a FY10 MPACT collaboration project. In addition, chemical processing for use in FC R&D was initiated, fission chamber detectors and a scanning alpha-particle spectrometer were developed, and foils were used in a preliminary LSDS experiment at a LANL/LANSCE in Sept. of 2010. The as-received U3O8 powder must be chemically processed to convert it to another chemical form while maintaining its purity, which then must be used to electro

Uranium Anodic Dissolution under Slightly Alkaline Conditions Progress Report Full-Scale Demonstration with DU Foil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelis, A.; Brown, M. A.; Wiedmeyer, S.

2014-02-18

Argonne National Laboratory (Argonne) is developing an alternative method for digesting irradiated low enriched uranium (LEU) foil targets to produce 99Mo in neutral/alkaline media. This method consists of the electrolytic dissolution of irradiated uranium foil in sodium bicarbonate solution, followed by precipitation of base-insoluble fission and activation products, and uranyl-carbonate species with CaO. The addition of CaO is vital for the effective anion exchange separation of 99MoO 4 2- from the fission products, since most of the interfering anions (e.g., CO 3 2-) are removed from the solution, while molybdate remains in solution. An anion exchange is used to retainmore » and to purify the 99Mo from the filtrate. The electrochemical dissolver has been designed and fabricated in 304 stainless-steel (SS), and tested for the dissolution of a full-size depleted uranium (DU) target, wrapped in Al foil. Future work will include testing with low-burn-up DU foil at Argonne and later with high-burn-up LEU foils at Oak Ridge National Laboratory.« less

Temperature measurements at material interfaces with thin-foil gauges

NASA Astrophysics Data System (ADS)

Morley, Mike; Chapman, David; Proud, William

2009-06-01

Measurements of shock heating are important in determining Equations of State that incorporate entropic effects. The use of thin-foil nickel gauges to measure shock heating in material was proposed by Rosenberg et al. in the 1980s. This research investigates the use of such commercial thin-foil gauges at interfaces between materials of different thermal and shock properties. The technique requires analysis of the resistance changes of the gauge which is a function of both temperature and stress. The response of manganin gauges to shock loading is well understood, and was used to calibrate for the piezoresistive effect in nickel. Results are presented for a variety of well-characterised materials and the applicability of the proposed method discussed.

Temperature Measurements at Material Interfaces with Thin-Foil Gauges

NASA Astrophysics Data System (ADS)

Morley, Mike J.; Chapman, David J.; Proud, William G.

2009-12-01

Measurements of shock heating are important in determining Equations of State that incorporate entropic effects. The use of thin-foil nickel gauges to measure shock heating in material was proposed by Rosenberg et al. in the 1980s. This research investigates the use of such commercial thin-foil gauges at interfaces between materials of different thermal and shock properties. The technique requires analysis of the resistance changes of the gauge which is a function of both temperature and stress. The response of manganin gauges to shock loading is well understood, and was used to calibrate for the piezoresistive effect in nickel. Results are presented for a variety of well-characterised materials and the applicability of the proposed method discussed.

Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martini, R., E-mail: roberto.martini@imec.be; imec, Kapeldreef 75, 3001 Leuven; Kepa, J.

2014-10-27

We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process.more » A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.« less

MULPEX: A compact multi-layered polymer foil collector for micrometeoroids and orbital debris

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MUlti- Layer Polymer EXperiment (MULPEX) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 and 40 μm) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 μm olivine) and space debris (4 μm alumina and 1 mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

MULPEX: a compact multi-layered polymer foil collector for micrometeoroids and orbital debris.

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MULPEX (MUlti-Layer Polymer EXperiment) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 micron and 40 micron) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 micron olivine) and space debris (4 micron alumina and 1mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

Optical temperature sensing on flexible polymer foils

NASA Astrophysics Data System (ADS)

Sherman, Stanislav; Xiao, Yanfen; Hofmann, Meike; Schmidt, Thomas; Gleissner, Uwe; Zappe, Hans

2016-04-01

In contrast to established semiconductor waveguide-based or glass fiber-based integrated optical sensors, polymerbased optical systems offer tunable material properties, such as refractive index or viscosity, and thus provide additional degrees of freedom for sensor design and fabrication. Of particular interest in sensing applications are fully-integrated optical waveguide-based temperature sensors. These typically rely on Bragg gratings which induce a periodic refractive index variation in the waveguide so that a resonant wavelength of the structure is reflected.1,2 With broad-band excitation, a dip in the spectral output of the waveguide is thus generated at a precisely-defined wavelength. This resonant wavelength depends on the refractive index of the waveguide and the grating period, yet both of these quantities are temperature dependent by means of the thermo-optic effect (change in refractive index with temperature) and thermal expansion (change of the grating period with temperature). We show the design and fabrication of polymer waveguide-integrated temperature sensors based on Bragggratings, fabricated by replication technology on flexible PMMA foil substrates. The 175 μm thick foil serves as lower cladding for a polymeric waveguide fabricated from a custom-made UV-crosslinkable co-monomer composition. The fabrication of the grating structure includes a second replication step into a separate PMMA-foil. The dimensions of the Bragg-gratings are determined by simulations to set the bias point into the near infrared wavelength range, which allows Si-based detectors to be used. We present design considerations and performance data for the developed structures. The resulting sensor's signal is linear to temperature changes and shows a sensitivity of -306 nm/K, allowing high resolution temperature measurements.

Simulation of thin aluminium-foil in the packaging industry

NASA Astrophysics Data System (ADS)

Eskil, Andreasson; Lindström, Tommy; Käck, Britta; Malmberg, Christoffer; Asp, Ann-Magret

2017-10-01

This work present an approach of how to account for the anisotropic mechanical material behaviour in the simulation models of the thin aluminium foil layer (≈10 µm) used in the Packaging Industry. Furthermore, the experimental results from uniaxial tensile tests are parameterised into an analytical expression and the slope of the hardening subsequently extended way beyond the experimental data points. This in order to accommodate the locally high stresses present in the experiments at the neck formation. An analytical expression, denominated Ramberg-Osgood, is used to describe the non-linear mechanical behaviour. Moreover it is possible with a direct method to translate the experimental uniaxial tensile test results into useful numerical material model parameters in Abaqus™. In addition to this the extended material behaviour including the plastic flow i.e. hardening, valid after onset of localisation, the described procedure can also capture the microscopic events, i.e. geometrical thinning, ongoing in the deformation of the aluminium foil. This method has earlier successfully been applied by Petri Mäkelä for paperboard material [1]. The engineering sound and parameterised description of the mechanical material behaviour facilitates an efficient categorisation of different aluminium foil alloys and aid the identification of the correct anisotropic (RD/TD/45°) mechanical material behaviour derived from the physical testing.

Triton Hodge Test: Improved Protocol for Modified Hodge Test for Enhanced Detection of NDM and Other Carbapenemase Producers

PubMed Central

Pasteran, Fernando; Gonzalez, Lisandro J.; Albornoz, Ezequiel; Bahr, Guillermo; Vila, Alejandro J.

2015-01-01

Accurate detection of carbapenemase-producing Gram-negative bacilli is of utmost importance for the control of nosocomial spread and the initiation of appropriate antimicrobial therapy. The modified Hodge test (MHT), a carbapenem inactivation assay, has shown poor sensitivity in detecting the worldwide spread of New Delhi metallo-β-lactamase (NDM). Recent studies demonstrated that NDM is a lipoprotein anchored to the outer membrane in Gram-negative bacteria, unlike all other known carbapenemases. Here we report that membrane anchoring of β-lactamases precludes detection of carbapenemase activity by the MHT. We also show that this limitation can be overcome by the addition of Triton X-100 during the test, which allows detection of NDM. We propose an improved version of the assay, called the Triton Hodge test (THT), which allows detection of membrane-bound carbapenemases with the addition of this nonionic surfactant. This test was challenged with a panel of 185 clinical isolates (145 carrying known carbapenemase-encoding genes and 40 carbapenemase nonproducers). The THT displayed test sensitivity of >90% against NDM-producing clinical isolates, while improving performance against other carbapenemases. Ertapenem provided the highest sensitivity (97 to 100%, depending on the type of carbapenemase), followed by meropenem (92.5 to 100%). Test specificity was not affected by the addition of Triton (87.5% and 92.5% with ertapenem and meropenem, respectively). This simple inexpensive test confers a large improvement to the sensitivity of the MHT for the detection of NDM and other carbapenemases. PMID:26719442

Fission foil detector calibrations with high energy protons

NASA Technical Reports Server (NTRS)

Benton, E. V.; Frank, A. L.

1995-01-01

Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

A Monte Carlo studies of the entrance foil material in a target assembly for FDG production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merouani, A.; El Khayati, N.; EL Ghayour, A.

2015-07-01

In this work, a Monte Carlo simulation was performed for different entrance foil Materials in the target assembly for [{sup 18}F] FDG production, to investigate the neutron generations in the entrance foil. However, the objective is to study a materials that has the more or less similar mechanical properties as the Havar{sup R} foil with less generation of secondary particles and without affecting, the yield of FDG production. (authors)

Flexible phosphorescent OLEDs on metal foil for military and commercial applications

NASA Astrophysics Data System (ADS)

Chwang, Anna; Lu, JengPing; Shih, Chinwen; Tung, Yeh-Jiun; Hewitt, Richard; Hack, Michael; Ho, Jackson; Brown, Julie

2005-05-01

We report recent advances in the development of low power consumption, emissive, flexible active matrix displays through integration of top emitting phosphorescent OLED (T-PHOLED) and poly-Si TFT backplane technologies. The displays are fabricated on flexible stainless steel foil. The T-PHOLEDs are based on UDC phosphorescent OLED technology, and the backplane is based on PARC's Excimer Laser Annealed (ELA) poly-Si TFT process. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

Small scale mechanical characterization of thin foil materials via pin load microtesting

DOE PAGES

Wheeler, Robert; Pandey, Amit; Shyam, Amit; ...

2015-05-06

In situ scanning electron microscope (SEM) experiments, where small-scale mechanical tests are conducted on micro- and nanosized specimens, allow direct visualization of elastic and plastic responses over the entirety of the volume being deformed. This enables precise spatial and temporal correlation of slip events contributing to the plastic flow evidenced in a stress–strain curve. A new pin-loading methodology has been employed, in situ within the SEM, to conduct microtensile tests on thin polycrystalline metal foils. This approach can be tailored to a specific foil whose particular grain size may range from microns to tens of microns. Manufacture of the specializedmore » pin grip was accomplished via silicon photolithography-based processing followed by subsequent focused ion beam finishing. Microtensile specimen preparation was achieved by combining a stencil mask methodology employing broad ion beam sputtering along with focused ion beam milling in the study of several metallic foil materials. Finite-element analyses were performed to characterize the stress and strain distributions in the pin grip and micro-specimen under load. Furthermore, under appropriately conceived test conditions, uniaxial stress–strain responses measured within these foils by pin-load microtensile testing exhibit properties consistent with larger scale tests.« less

Porus electrode comprising a bonded stack of pieces of corrugated metal foil

NASA Technical Reports Server (NTRS)

Mccallum, J. (Inventor)

1973-01-01

An electrode suitable for use in an electrochemical cell is described. The electrode is composed of a porous conductive support with a bonded stack of pieces of thin corrugated nickel foil where the corrugations are oriented approximately perpendicular to the sides of the electrode and form an array of passages through the electrode. Active material such as cadmium hydroxide or nickel hydroxide is uniformly distributed within the passages. The support may comprise also a piece of thin flat nickel foil between adjacent pieces of the corrugated foil, forming a barrier between the passages formed on each side of it. Typically the corrugations in the odd corrugated layers are oriented at a small angle from the perpendicular in one direction and the corrugations in the even corrugated layers are oriented at a small angle from the perpendicular in the opposite direction.

Propulsive performance of biologically inspired flapping foils at high Reynolds numbers.

PubMed

Techet, Alexandra H

2008-01-01

Propulsion and maneuvering underwater by flapping foil motion, optimized through years of evolution, is ubiquitous in nature, yet marine propulsors inspired by examples of highly maneuverable marine life or aquatic birds are not widely implemented in engineering. Performance data from flapping foils, moving in a rolling and pitching motion, are presented at high Reynolds numbers, Re=Uc/nu, or O(10(4)), where U is the relative inflow velocity, c is the chord length of the foil, and nu is the kinematic viscosity of the fluid, from water tunnel experiments using a foil actuator module designed after an aquatic penguin or turtle fin. The average thrust coefficients and efficiency measurements are recorded over a range of kinematic flapping amplitudes and frequencies. Results reveal a maximum thrust coefficient of 2.09, and for low values of angle of attack the thrust generally increases with Strouhal number, without much penalty to efficiency. Strouhal number is defined as St=2h(0)f/U, where f is the frequency of flapping, and 2h(0) is the peak-to-peak amplitude of flapping. The thrust and efficiency contour plots also present a useful performance trend where, at low angles of attack, high thrust and efficiency can be gained at sufficiently high Strouhal numbers. Understanding the motion of aquatic penguins and turtle wings and emulating these motions mechanically can yield insight into the hydrodynamics of how these animals swim and also improve performance of biologically inspired propulsive devices.

Extraction of Solar Wind Nitrogen and Noble Gases From the Genesis Gold Foil Collector

NASA Astrophysics Data System (ADS)

Schlutter, D. J.; Pepin, R. O.

2005-12-01

The Genesis gold foil is a bulk solar wind collector, integrating fluences from all three of the wind regimes. Pyrolytic extraction of small foil samples at Minnesota yielded He fluences, corrected for backscatter, in good agreement with measurements by on-board spacecraft instruments, and He/Ne elemental ratios close to those implanted in collector foils deployed on the lunar surface during the Apollo missions. Isotopic distributions of He, Ne and Ar are under study. Pyrolysis to temperatures above the gold melting point generates nitrogen blanks large enough to obscure the solar-wind nitrogen component. An alternative technique for nitrogen and noble gas extraction, by room-temperature amalgamation of the gold foil surface, will be discussed. Ne and Ar releases in preliminary tests of this technique on small foil samples were close to 100% of the amounts expected from the high-temperature pyrolysis yields, indicating that amalgamation quantitatively liberates gases from several hundred angstroms deep in the gold, beyond the implantation depth of most of the solar wind. Present work is focused on two problems currently interfering with accurate nitrogen measurements at the required picogram to sub-picogram levels: a higher than expected blank likely due to tiny air bubbles rolled into the gold sheet during fabrication, and the presence of a refractory hydrocarbon film on Genesis collector surfaces (the "brown stain") that, if left in place on the foil, shields the underlying gold from mercury attack. We have found, however, that the film is efficiently removed within tens of seconds by oxygen plasma ashing. Potential nitrogen contaminants introduced during the crash of the sample return canister are inert in amalgamation, and so are not hazards to the measurements.

Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils

NASA Astrophysics Data System (ADS)

Osman, H.; Borhana, A.; Tamin, M. N.

2014-08-01

Creep rupture properties of austenitic stainless steel foil, 347SS, used in compact recuperators have been evaluated at 700 °C in the stress range of 54-221 MPa to establish the baseline behavior for its extended use. Creep curves of the foil show that the primary creep stage is brief and creep life is dominated by tertiary creep deformation with rupture lives in the range of 10-2000 h. Results are compared with properties of bulk specimens tested at 98 and 162 MPa. Thin foil 347SS specimens were found to have higher creep rates and higher rupture ductility than their bulk specimen counterparts. Power law relationship was obtained between the minimum creep rate and the applied stress with stress exponent value, n = 5.7. The value of the stress exponent is indicative of the rate-controlling deformation mechanism associated with dislocation creep. Nucleation of voids mainly occurred at second-phase particles (chromium-rich M23C6 carbides) that are present in the metal matrix by decohesion of the particle-matrix interface. The improvement in strength is attributed to the precipitation of fine niobium carbides in the matrix that act as obstacles to the movement of dislocations.

Dye foils with increased durability for passive Q-switching in a 1064 nm laser

NASA Astrophysics Data System (ADS)

Mierczyk, Z.; Kwasny, M.; Czeszko, J.

The results of spectral gel permeation chromatography and differential thermal analysis investigations of structures of dye foils consisting of bis-(4-dimethyl-amino-dithio-benzil)-nickel dye suspended in polymethylmethacrylate matrix, to be used for passive Q-switching in a 1064 nm laser, are reported. Results of experimental measurements and of numerical calculations of thermal and generating properties, and of the endurance of passive foil type Q-switches in the resonator of YAG:Nd(3+) laser are also presented. Optimization of polymerization conditions has enabled the production of dye foils with high thermal and photochemical resistance, which give stable operation of a giant pulsed laser.

Dye Foils With Increased Durability For Passive Q-Switching In A 1064 Nm Laser.

NASA Astrophysics Data System (ADS)

Mierczyk, Z.; Kwasny, M.; Czeszko, J.

1987-10-01

The results of spectral (IR, UV-VIS, H NMR) , gel permeation chromatography and differential thermal analysis investigations of structures of dye foils consisting of bis-(4-dimethyl-amino-dithio-benzil)-nickel dye suspended in polymethylmethacrylate matrix, to be used for passive Q-switching in a 1064 nm laser, are reported. Results of experimental measurements and of numerical calculations of thermal and generating properties, and of the endurance of passive foil type Q-switches in the resona-tor of YAG:Nd3+ laser are also presented. Optimization of polymerization conditions has enabled the production of dye foils with high thermal and photochemical resistance, which give stable operation of a giant pulsed laser.

Foil chaff ejection systems for rocket-borne measurement of neutral winds in the mesosphere and lower thermosphere

NASA Astrophysics Data System (ADS)

Koizumi, Yoshiko; Shimoyama, Manabu; Oyama, Koh-Ichiro; Murayama, Yasuhiro; Tsuda, Toshitaka; Nakamura, Takuji

2004-07-01

The foil chaff technique has been used on microrockets such as "Viper" for a long time to measure neutral winds with high altitude resolution in the mesosphere and lower thermosphere. We have developed two new foil chaff storage and ejection systems for muti-instrumented sounding rockets. The first system uses a spring loaded split cylinder which holds the foil chaff, housed in an outer cylinder. The shaft of the split cylinder is kept in place by a lock plate and a stainless steel wire. The split cylinder is ejected by cutting the wire. The second system is of differential pressure type. The cap of an airtight cylinder has a shaft and a sponge piece for sweeping out the foil chaff. The cylinder is sealed at ground level and at the desired height of release, the cap comes out due to differential pressure and brings out the foil chaff. Both these systems were successfully tested on a Japanese sounding rocket in January 2000, releasing about 20 000 pieces of foil chaff during the rocket's descent. Neutral winds were measured in the height range of 85.5-95.0 km with a height resolution of 300 m.

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate.

PubMed

Cirin, Dejan M; Poša, Mihalj M; Krstonošić, Veljko S

2011-12-29

In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100) or anionic (sodium lauryl ether sulfate) surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate.

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate

PubMed Central

2011-01-01

Background In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100) or anionic (sodium lauryl ether sulfate) surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. Results The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. Conclusion It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate. PMID:22206681

Ground effect on a self-propelled undulatory foil

NASA Astrophysics Data System (ADS)

Zhang, Dong; Chao, Liming; Pan, Guang

2018-04-01

The unsteady ground effect on a self-propelled undulatory foil is numerically investigated in this paper. The situation can be widely found in nature especially for fish swimming near the ground. In this study, frequency varies from 0.1 Hz to 2 Hz and distance from the ground varies from 0.2 L to 1 L. Under most kinematics, the ground has a negative effect on the performance of the foil. The swimming velocity slows down, power spend increases and swimming economy reduces. The higher frequency can produce a larger negative effect. Only at the low frequencies f = 0.1 Hz, 0.25 Hz and 0.5 Hz with distance of 0.2 L the velocity can be enhanced by 18%, 6%, 0.8%, respectively. The lift production is found to be increased. The link between the performance and the wake dynamics is also established by studying the vortex structures.

High fidelity studies of exploding foil initiator bridges, Part 2: Experimental results

NASA Astrophysics Data System (ADS)

Neal, William; Bowden, Mike

2017-01-01

Simulations of high voltage detonators, such as Exploding Bridgewire (EBW) and Exploding Foil Initiators (EFI), have historically been simple, often empirical, one-dimensional models capable of predicting parameters such as current, voltage, and in the case of EFIs, flyer velocity. Experimental methods have correspondingly generally been limited to the same parameters. With the advent of complex, first principles magnetohydrodynamic codes such as ALEGRA MHD, it is now possible to simulate these components in three dimensions and predict greater range of parameters than before. A significant improvement in experimental capability was therefore required to ensure these simulations could be adequately verified. In this second paper of a three part study, data is presented from a flexible foil EFI header experiment. This study has shown that there is significant bridge expansion before time of peak voltage and that heating within the bridge material is spatially affected by the microstructure of the metal foil.

Analytic Modeling of the Hydrodynamic, Thermal, and Structural Behavior of Foil Thrust Bearings

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; DellaCorte, Christopher; Prahl, Joseph M.

2005-01-01

A simulation and modeling effort is conducted on gas foil thrust bearings. A foil bearing is a self acting hydrodynamic device capable of separating stationary and rotating components of rotating machinery by a film of air or other gaseous lubricant. Although simple in appearance these bearings have proven to be complicated devices in analysis. They are sensitive to fluid structure interaction, use a compressible gas as a lubricant, may not be in the fully continuum range of fluid mechanics, and operate in the range where viscous heat generation is significant. These factors provide a challenge to the simulation and modeling task. The Reynolds equation with the addition of Knudsen number effects due to thin film thicknesses is used to simulate the hydrodynamics. The energy equation is manipulated to simulate the temperature field of the lubricant film and combined with the ideal gas relationship, provides density field input to the Reynolds equation. Heat transfer between the lubricant and the surroundings is also modeled. The structural deformations of the bearing are modeled with a single partial differential equation. The equation models the top foil as a thin, bending dominated membrane whose deflections are governed by the biharmonic equation. A linear superposition of hydrodynamic load and compliant foundation reaction is included. The stiffness of the compliant foundation is modeled as a distributed stiffness that supports the top foil. The system of governing equations is solved numerically by a computer program written in the Mathematica computing environment. Representative calculations and comparisons with experimental results are included for a generation I gas foil thrust bearing.

Hydrogen and Palladium Foil: Two Classroom Demonstrations

ERIC Educational Resources Information Center

Klotz, Elsbeth; Mattson, Bruce

2009-01-01

In these two classroom demonstrations, students observe the reaction between H[subscript 2] gas and Pd foil. In the first demonstration, hydrogen and palladium combine within one minute at 1 atm and room temperature to yield the non-stoichiometric, interstitial hydride with formula close to the maximum known value, PdH[subscript 0.7]. In the…

The Fluid Foil: The Seventh Simple Machine

ERIC Educational Resources Information Center

Mitts, Charles R.

2012-01-01

A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

Triton Hodge Test: Improved Protocol for Modified Hodge Test for Enhanced Detection of NDM and Other Carbapenemase Producers.

PubMed

Pasteran, Fernando; Gonzalez, Lisandro J; Albornoz, Ezequiel; Bahr, Guillermo; Vila, Alejandro J; Corso, Alejandra

2016-03-01

Accurate detection of carbapenemase-producing Gram-negative bacilli is of utmost importance for the control of nosocomial spread and the initiation of appropriate antimicrobial therapy. The modified Hodge test (MHT), a carbapenem inactivation assay, has shown poor sensitivity in detecting the worldwide spread of New Delhi metallo-β-lactamase (NDM). Recent studies demonstrated that NDM is a lipoprotein anchored to the outer membrane in Gram-negative bacteria, unlike all other known carbapenemases. Here we report that membrane anchoring of β-lactamases precludes detection of carbapenemase activity by the MHT. We also show that this limitation can be overcome by the addition of Triton X-100 during the test, which allows detection of NDM. We propose an improved version of the assay, called the Triton Hodge test (THT), which allows detection of membrane-bound carbapenemases with the addition of this nonionic surfactant. This test was challenged with a panel of 185 clinical isolates (145 carrying known carbapenemase-encoding genes and 40 carbapenemase nonproducers). The THT displayed test sensitivity of >90% against NDM-producing clinical isolates, while improving performance against other carbapenemases. Ertapenem provided the highest sensitivity (97 to 100%, depending on the type of carbapenemase), followed by meropenem (92.5 to 100%). Test specificity was not affected by the addition of Triton (87.5% and 92.5% with ertapenem and meropenem, respectively). This simple inexpensive test confers a large improvement to the sensitivity of the MHT for the detection of NDM and other carbapenemases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Field and laboratory evaluations of commercial and next–generation alumina-forming austenitic foil for advanced recuperators

DOE PAGES

Pint, Bruce A.; Dryepondt, Sebastien N.; Brady, Michael P.; ...

2016-07-19

Alumina-forming austenitic (AFA) steels represent a new class of corrosion- and creep-resistant austenitic steels designed to enable higher temperature recuperators. Field trials are in progress for commercially rolled foil with widths over 39 cm. The first trial completed 3000 hrs in a microturbine recuperator with an elevated turbine inlet temperature and showed limited degradation. A longer microturbine trial is in progress. A third exposure in a larger turbine has passed 16,000 hrs. Furthermore, to reduce alloy cost and address foil fabrication issues with the initial AFA composition, several new AFA compositions are being evaluated in creep and laboratory oxidation testingmore » at 650–800 °C and the results compared to commercially fabricated AFA foil and conventional recuperator foil performance.« less

Numerically Simulating Collisions of Plastic and Foam Laser-Driven Foils

NASA Astrophysics Data System (ADS)

Zalesak, S. T.; Velikovich, A. L.; Schmitt, A. J.; Aglitskiy, Y.; Metzler, N.

2007-11-01

Interest in experiments on colliding planar foils has recently been stimulated by (a) the Impact Fast Ignition approach to laser fusion [1], and (b) the approach to a high-repetition rate ignition facility based on direct drive with the KrF laser [2]. Simulating the evolution of perturbations to such foils can be a numerical challenge, especially if the initial perturbation amplitudes are small. We discuss the numerical issues involved in such simulations, describe their benchmarking against recently-developed analytic results, and present simulations of such experiments on NRL's Nike laser. [1] M. Murakami et al., Nucl. Fusion 46, 99 (2006) [2] S. P. Obenschain et al., Phys. Plasmas 13, 056320 (2006).

Fabrication and Metrology of High-Precision Foil Mirror Mounting Elements

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2002-01-01

During the period of this Cooperative Agreement, MIT (Massachusetts Institute of Technology) developed advanced methods for applying silicon microstructures for the precision assembly of foil x-ray optics in support of the Constellation-X Spectroscopy X-ray Telescope (SXT) development effort at Goddard Space Flight Center (GSFC). MIT developed improved methods for fabricating and characterizing the precision silicon micro-combs. MIT also developed and characterized assembly tools and several types of metrology tools in order to characterize and reduce the errors associated with precision assembly of foil optics. Results of this effort were published and presented to the scientific community and the GSFC SXT team. A bibliography of papers and presentations is offered.

Evolution of graphene islands growing on Cu foils

NASA Astrophysics Data System (ADS)

Wofford, Joseph; Nie, Shu; Bartelt, Norman; McCarty, Kevin; Dubon, Oscar

2011-03-01

Using low-energy electron microscopy we investigate, in real time, the growth of graphene monolayers on Cu foils. Graphene islands evolve from an initially compact form into an increasingly ramified, four-lobed shape, reflecting the symmetry of the (100)-textured Cu surface. Diffraction analysis reveals that each lobe is an individual graphene domain, differentiated by a rotation about the film normal, making the islands polycrystalline. An inspection of the morphological evolution of the graphene lobes shows the growth fronts posses an angularly dependent velocity, which is consistent with a growth mode dominated by edge kinetics. The fast growth direction of each lobe tends to align with the 001 in-plane directions of the Cu surface but not with a high symmetry direction of the graphene lattice. Finally, the implications of this unexpected growth mechanism on the formation of high-quality graphene films on Cu foils are evaluated. Supported by BES/USDOE under contracts #DE-AC04-94AL85000 and #DE-AC02-05CH11231.

Effects of the shape of the foil corners on the irradiation performance of U10Mo alloy based monolithic mini-plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozaltun, Hakan; Medvedev, Pavel G

2015-06-01

Monolithic plate-type fuel is a fuel form being developed for high performance research and test reactors to minimize the use of enriched material. These fuel elements are comprised of a high density, low enrichment, U-Mo alloy based fuel foil, sandwiched between Zirconium liners and encapsulated in Aluminum cladding. The use of a high density fuel in a foil form presents a number of fabrication and operational concerns, such as: foil centering, flatness of the foil, fuel thickness variation, geometrical tilting, foil corner shape etc. To benchmark this new design, effects of various geometrical and operational variables on irradiation performance havemore » been evaluated. As a part of these series of sensitivity studies, the shape of the foil corners were studied. To understand the effects of the corner shapes of the foil on thermo-mechanical performance of the plates, a behavioral model was developed for a selected plate from RERTR-12 experiments (Plate L1P785). Both fabrication and irradiation processes were simulated. Once the thermo-mechanical behavior the plate is understood for the nominal case, the simulations were repeated for two additional corner shapes to observe the changes in temperature, displacement and stress-strain fields. The results from the fabrication simulations indicated that the foil corners do not alter the post-fabrication stress-strain magnitudes. Furthermore, the irradiation simulations revealed that post-fabrication stresses of the foil would be relieved very quickly in operation. While, foils with chamfered and filleted corners yielded stresses with comparable magnitudes, they are slightly lower in magnitudes, and provided a more favorable mechanical response compared with the foil with sharp corners.« less

Ablative Rayleigh-Taylor and Richtmyer-Meshkov Instabilities in Laser-Accelerated Colliding Foils

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Metzler, N.; Karasik, M.; Serlin, V.; Weaver, J.; Obenschain, S. P.; Oh, J.; Schmitt, A. J.; Velikovich, A. L.; Zalesak, S. T.; Gardner, J. H.; Harding, E. C.

2008-11-01

In our experiments done on the Nike KrF laser, we study instability growth at shock-decelerated interfaces in planar colliding-foil experiments. We use streaked monochromatic (1.86 keV) x-ray face-on imaging diagnostics to measure the areal mass modulation growth caused by the instability. Higher x-ray energies up to 5.25 keV are used to follow the shock propagation as well as the 1D dynamics of the collision. While a laser-driven foil is accelerated towards the stationary low-density foam layer, an ablative RT instability develops. Having reached a high velocity, the foil hits the foam layer. The impact generates strong shocks in the plastic and in the foam. The reflected shock wave re-shocks the ablation front, its acceleration stops, and so does the observed RT growth. This is followed by areal mass oscillations due to the ablative RM instability and feedout mechanisms, of which the latter dominates.

Evidence of circular Rydberg states in beam-foil experiments: Role of the surface wake field

NASA Astrophysics Data System (ADS)

Sharma, Gaurav; Puri, Nitin K.; Kumar, Pravin; Nandi, T.

2017-12-01

We have employed the concept of the surface wake field to model the formation of the circular Rydberg states in the beam-foil experiments. The experimental studies of atomic excitation processes show the formation of circular Rydberg states either in the bulk of the foil or at the exit surface, and the mechanism is explained by several controversial theories. The present model is based on the interesting fact that the charge state fraction as well as the surface wake field depend on the foil thickness and it resolves a long-standing discrepancy on the mechanism of the formation of circular Rydberg states. The influence of exit layers is twofold. Initially, the high angular momentum Rydberg states are produced in the last layers of the foil by the Stark switching due to the bulk wake field and finally, they are transferred to the circular Rydberg states as a single multiphoton process due to the influence of the surface wake field.

The stopping power and energy straggling of light ions in graphene oxide foils

NASA Astrophysics Data System (ADS)

Mikšová, R.; Macková, A.; Malinský, P.; Sofer, Z.

2017-09-01

Energy-loss and straggling experiments were performed using 2-4 MeV 1H+ and 7.4-9.0 MeV 4He2+ ions in graphene oxide foils by the transmission technique. The thickness of the graphene oxide foils was determined using a detailed image analysis of a graphene oxide cut, which was used to refine the graphene oxide density. The density was determined by the standard technique of micro-balance weighing. The stoichiometry of the graphene oxide foils before the irradiation was determined by Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA) using 2 and 2.5 MeV 4He+. The measured energy stopping powers for hydrogen and helium ions in graphene oxide were compared with the predictions obtained from the SRIM-2013 code. The energy straggling was compared with that calculated using Bohr's, Bethe-Livingston and Yang predictions. The results show that the stopping power of graphene oxide foils irradiated by both ion species decreases with increasing energies, the differences between the measured and predicted values being below 3.8%. The energy straggling determined in our experiment is higher than Bohr's and Bethe-Livingston predicted values; the predictions by Yang are in better agreement with our experiment.

Triton: The Connection between Rosetta, New Horizons and a future Ice Giants Mission

NASA Astrophysics Data System (ADS)

Mandt, K.; Luspay-Kuti, A.; Mousis, O.

2017-12-01

Several planetary missions have made observations intended to evaluate the origin and evolution of volatiles in solar system atmospheres. This is an important topic that connects how planets, moons and small bodies formed to the question of past or present habitability. Comet isotope observations have been ongoing and have played a crucial role in this research. Measurements of the D/H in cometary water and 14N/15N in NH3, in particular, have been critical for evaluating the origin of water and nitrogen in the terrestrial planet atmospheres and for that of Saturn's moon Titan. We have conducted comparative studies modeling the escape, photochemistry and evolution of the atmospheres of Titan and Pluto to try to understand whether the nitrogen in these atmospheres originated as N2 or NH3 in the protosolar nebula. The origin of Titan's nitrogen has been well constrained, but uncertainties about isotope processes in Pluto's atmosphere leave the origin of Pluto's nitrogen difficult to resolve. Because of their similarities, Triton is subject to the same uncertainties and is of particular interest for understanding the origin of Triton's and Pluto's volatiles as well as of Kuiper Belt Objects in general. We will discuss how Rosetta, New Horizons and a future Ice Giants mission will each contribute to understanding the origin of nitrogen in these atmospheres and to the origin of volatiles in atmospheres throughout outer solar system.

Multiple-foil microabrasion package (A0023)

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Ashworth, D. G.; Carey, W. C.; Flavill, R. P.; Jennison, R. C.

1984-01-01

The specific scientific objectives of this experiment are to measure the spatial distribution, size, velocity, radiance, and composition of microparticles in near-Earth space. The technological objectives are to measure erosion rates resulting from microparticle impacts and to evaluate thin-foil meteor 'bumpers'. The combinations of sensitivity and reliability in this experiment will provide up to 1000 impacts per month for laboratory analysis and will extend current sensitivity limits by 5 orders of magnitude in mass.

Eddy current probe with foil sensor mounted on flexible probe tip and method of use

DOEpatents

Viertl, John R. M.; Lee, Martin K.

2001-01-01

A pair of copper coils are embedded in the foil strip. A first coil of the pair generates an electromagnetic field that induces eddy currents on the surface, and the second coil carries a current influenced by the eddy currents on the surface. The currents in the second coil are analyzed to obtain information on the surface eddy currents. An eddy current probe has a metal housing having a tip that is covered by a flexible conductive foil strip. The foil strip is mounted on a deformable nose at the probe tip so that the strip and coils will conform to the surface to which they are applied.

D-Cluster Converter Foil for Laser-Accelerated Deuteron Beams: Towards Deuteron-Beam-Driven Fast Ignition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miley, George H.

Fast Ignition (FI) uses Petawatt laser generated particle beam pulse to ignite a small volume called a pre-compressed Inertial Confinement Fusion (ICF) target, and is the favored method to achieve the high energy gain per target burn needed for an attractive ICF power plant. Ion beams such as protons, deuterons or heavier carbon ions are especially appealing for FI as they have relative straight trajectory, and easier to focus on the fuel capsule. But current experiments have encountered problems with the 'converter-foil' which is irradiated by the Petawatt laser to produce the ion beams. The problems include depletion of themore » available ions in the convertor foils, and poor energy efficiency (ion beam energy/ input laser energy). We proposed to develop a volumetrically-loaded ultra-high-density deuteron deuterium cluster material as the basis for converter-foil for deuteron beam generation. The deuterons will fuse with the ICF DT while they slow down, providing an extra 'bonus' energy gain in addition to heating the hot spot. Also, due to the volumetric loading, the foil will provide sufficient energetic deuteron beam flux for 'hot spot' ignition, while avoiding the depletion problem encountered by current proton-driven FI foils. After extensive comparative studies, in Phase I, high purity PdO/Pd/PdO foils were selected for the high packing fraction D-Cluster converter foils. An optimized loading process has been developed to increase the cluster packing fraction in this type of foil. As a result, the packing fraction has been increased from 0.1% to 10% - meeting the original Phase I goal and representing a significant progress towards the beam intensities needed for both FI and pulsed neutron applications. Fast Ignition provides a promising approach to achieve high energy gain target performance needed for commercial Inertial Confinement Fusion (ICF). This is now a realistic goal for near term in view of the anticipated ICF target burn at the National

Thin plastic foil X-ray optics with spiral geometry

NASA Astrophysics Data System (ADS)

Barbera, Marco; Mineo, Teresa; Perinati, Emanuele; Schnopper, Herbert W.; Taibi, Angelo

2007-09-01

Winding a plastic foil ribbon into spiral cylinder or spiral cones we can design and build single or multiple reflection X-ray grazing incidence focusing optics with potential applications in Astronomy as well as experimental physics. The use of thin plastic foils from common industrial applications and of a mounting technique which does not require the construction of mandrels make these optics very cost effective. A spiral geometry focusing optic produces an annular image of a point source with the angular size of the annulus depending mainly on the pitch of the winding and the focal length. We use a ray-tracing code to evaluate the performances of cylindrical, and double conical spiral geometry as a function of the design parameters e.g. focal length, diameter, optic length. Some preliminary results are presented on X-ray imaging tests performed on spiral cylindrical optics.

{001} Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

NASA Astrophysics Data System (ADS)

Yeo, Hong Goo; Trolier-McKinstry, Susan

2014-07-01

Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O3 (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, {001} oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO2 grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO3 films were integrated by CSD on the HfO2 coated substrates. A high level of {001} LaNiO3 and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ˜36 μC/cm2, while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e31,f| piezoelectric coefficient was around 10.6 C/m2 for hot-poled (001) oriented PZT film on Ni.

The Role of Radial Clearance on the Performance of Foil Air Bearings

NASA Technical Reports Server (NTRS)

Radil, Kevin; Howard, Samuel; Dykas, Brian

2002-01-01

Load capacity tests were conducted to determine how radial clearance variations affect the load capacity coefficient of foil air bearings. Two Generation III foil air bearings with the same design but possessing different initial radial clearances were tested at room temperature against an as-ground PS304 coated journal operating at 30,000 rpm. Increases in radial clearance were accomplished by reducing the journal's outside diameter via an in-place grinding system. From each load capacity test the bearing load capacity coefficient was calculated from the rule-of-thumb (ROT) model developed for foil air bearings. The test results indicate that, in terms of the load capacity coefficient, radial clearance has a direct impact on the performance of the foil air bearing. Each test bearing exhibited an optimum radial clearance that resulted in a maximum load capacity coefficient. Relative to this optimum value are two separate operating regimes that are governed by different modes of failure. Bearings operating with radial clearances less than the optimum exhibit load capacity coefficients that are a strong function of radial clearance and are prone to a thermal runaway failure mechanism and bearing seizure. Conversely, a bearing operating with a radial clearance twice the optimum suffered only a 20 percent decline in its maximum load capacity coefficient and did not experience any thermal management problems. However, it is unknown to what degree these changes in radial clearance had on other performance parameters, such as the stiffness and damping properties of the bearings.

Validation of MCNP NPP Activation Simulations for Decommissioning Studies by Analysis of NPP Neutron Activation Foil Measurement Campaigns

NASA Astrophysics Data System (ADS)

Volmert, Ben; Pantelias, Manuel; Mutnuru, R. K.; Neukaeter, Erwin; Bitterli, Beat

2016-02-01

In this paper, an overview of the Swiss Nuclear Power Plant (NPP) activation methodology is presented and the work towards its validation by in-situ NPP foil irradiation campaigns is outlined. Nuclear Research and consultancy Group (NRG) in The Netherlands has been given the task of performing the corresponding neutron metrology. For this purpose, small Aluminium boxes containing a set of circular-shaped neutron activation foils have been prepared. After being irradiated for one complete reactor cycle, the sets have been successfully retrieved, followed by gamma-spectrometric measurements of the individual foils at NRG. Along with the individual activities of the foils, the reaction rates and thermal, intermediate and fast neutron fluence rates at the foil locations have been determined. These determinations include appropriate corrections for gamma self-absorption and neutron self-shielding as well as corresponding measurement uncertainties. The comparison of the NPP Monte Carlo calculations with the results of the foil measurements is done by using an individual generic MCNP model functioning as an interface and allowing the simulation of individual foil activation by predetermined neutron spectra. To summarize, the comparison between calculation and measurement serve as a sound validation of the Swiss NPP activation methodology by demonstrating a satisfying agreement between measurement and calculation. Finally, the validation offers a chance for further improvements of the existing NPP models by ensuing calibration and/or modelling optimizations for key components and structures.

F-doped VO2 nanoparticles for thermochromic energy-saving foils with modified color and enhanced solar-heat shielding ability.

PubMed

Dai, Lei; Chen, Shi; Liu, Jianjun; Gao, Yanfeng; Zhou, Jiadong; Chen, Zhang; Cao, Chuanxiang; Luo, Hongjie; Kanehira, Minoru

2013-07-28

F-doped VO2 (M1) nanoparticles were prepared via one-pot hydrothermal synthesis. The F-doping can minimise the size of the VO2 (M1) nanoparticles, induce a homogeneous size distribution and effectively decrease the phase transition temperature to 35 °C at 2.93% F in VO2. VO2 smart glass foils obtained by casting these nanoparticles exhibit excellent thermochromism in the near-infrared region, which suggests that these foils can be used for energy-efficient glass. Compared to a pure VO2 foil, the 2.93% F-doped VO2 foil exhibits an increased solar-heat shielding ability (35.1%) and a modified comfortable colour, while still retaining an excellent solar modulation ability (10.7%) and an appropriate visible transmittance (48.7%). The F-doped VO2 foils are the first to simultaneously meet the requirements of a reduced phase transition temperature, diluted colour and excellent thermochromic properties, and these properties make the further improved F-doped VO2 foils suitable for commercial applications in energy efficient glass.

Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency

NASA Astrophysics Data System (ADS)

Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

2018-03-01

Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

Antihyperlipidemic activity of Ichnocarpus frutescens in triton WR-1339-induced and high-fat diet animals.

PubMed

Saravanan, M; Pandikumar, P; Prakash Babu, N; Ignacimuthu, S

2011-10-01

Ichnocarpus frutescens (L.) R.Br. (Apocynaceae) is used to treat diabetes and hyperlipidemia in folk medicine. The crude methanol extract and fractions of I. frutescens were investigated for antihyperlipidemic effect. Fresh leaves of I. frutescens were extracted with methanol and fractionated with hexane, benzene, ethyl acetate, acetone, and methanol. The active acetone fraction was subfractionated, which resulted in active fraction 3. The antihyperlipidemic effects of the methanol extract and fractions of I. frutescens were studied in triton WR-1339-induced and high-fat diet (HFD) obese animals. Further, lipid absorption and excretion were studied. The methanol extract significantly reduced total cholesterol (TC) by 29.63% and triglyceride (Tg) by 51.10% at 400 mg/kg in triton WR-1339-induced animals and significantly reduced TC (27.81%) and Tg (37.03%) at 400 mg/kg in HFD animals. Fraction 3 showed significant reduction in TC (25.03%) and Tg (58.05%) at 200 mg/kg. Feeding of HFD consisting 3% of fraction 3 increased feces weight and Tg level in mice. Fraction 3, showed significant decrease in plasma Tg level at the second hour, after oral administration of the lipid emulsion to rats. The observed properties apparently validate the folk medicinal use of this plant in amelioration of hyperlipidemia.

Numerical Investigations on Aerodynamic Forces of Deformable Foils in Hovering Motions

NASA Astrophysics Data System (ADS)

Zhao, Yong; Yin, Zhen; Su, Xiaohui; Zhang, Jiantao; Cao, Yuanwei

2017-09-01

The aerodynamic effects of wing deformation for hover flight are numerically investigated by a two-dimensional finite-volume (FV) Arbitrary Langrangian Eulerian (ALE) Navier-Stokes solver. Two deformation models are employed to study these effects in this paper, which are a full deformation model and a partial deformation one. Attentions are paid to the generation and development of leading edge vortex (LEV) and trailing edge vortex (TEV) which may illustrate the differences of lift force generation mechanisms from those of rigid wings. Moreover, lift coefficient Cl, drag coefficient Cd, and figure of merit, as well as energy consumption in hovering motion for different deformation foil models, are also studied. The results show that the deformed amplitude, 0.1*chord, among the cases simulated is an optimized camber amplitude for full deformation. The results obtained from the partial deformation foil model show that both Cl and Cd decrease with the increase of camber amplitude. It is found that the effect of deformation in the partial deformation model does not enhance lift force due to unfavorable camber. But TEV is significantly changed by the local AOA due to the deformation of the foil. Introduction.

Bi-Directional Ion Emission from Massive Gold Cluster Impacts on Nanometric Carbon Foils.

PubMed

Debord, J Daniel; Della-Negra, Serge; Fernandez-Lima, Francisco A; Verkhoturov, Stanislav V; Schweikert, Emile A

2012-04-12

Carbon cluster emission from thin carbon foils (5-40 nm) impacted by individual Au(n) (+q) cluster projectiles (95-125 qkeV, n/q = 3-200) reveals features regarding the energy deposition, projectile range, and projectile fate in matter as a function of the projectile characteristics. For the first time, the secondary ion emission from thin foils has been monitored simultaneously in both forward and backward emission directions. The projectile range and depth of emission were examined as a function of projectile size, energy, and target thickness. A key finding is that the massive cluster impact develops very differently from that of a small polyatomic projectile. The range of the 125 qkeV Au(100q) (+q) (q ≈ 4) projectile is estimated to be 20 nm (well beyond the range of an equal velocity Au(+)) and projectile disintegration occurs at the exit of even a 5 nm thick foil.

Crystallographic texture of straight-rolled ?-uranium foils via neutron and X-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Einhorn, J. R.; Steiner, M. A.; Vogel, S. C.

The texture of recrystallized straight-rolled ?-uranium foils, a component in prospective irradiation target designs for medical isotope production, has been measured by neutron diffraction, as well as X-ray diffraction using both Cu and Mo sources. Variations in the penetration depth of neutron and X-ray radiation allow for determination of both the bulk and surface textures. The bulk ?-uranium foil texture is similar to the warm straight-rolled plate texture, with the addition of a notable splitting of the (001) poles along the transverse direction. The surface texture of the foils is similar to the bulk, with an additional (001) texture componentmore » that is oriented between the rolling and normal directions. Differences between the surface and bulk textures are expected to arise from shear forces during the rolling process and the influence that distinct strain histories have on subsequent texture evolution during recrystallization.« less

Crystallographic texture of straight-rolled ?-uranium foils via neutron and X-ray diffraction

DOE PAGES

Einhorn, J. R.; Steiner, M. A.; Vogel, S. C.; ...

2017-05-25

The texture of recrystallized straight-rolled ?-uranium foils, a component in prospective irradiation target designs for medical isotope production, has been measured by neutron diffraction, as well as X-ray diffraction using both Cu and Mo sources. Variations in the penetration depth of neutron and X-ray radiation allow for determination of both the bulk and surface textures. The bulk ?-uranium foil texture is similar to the warm straight-rolled plate texture, with the addition of a notable splitting of the (001) poles along the transverse direction. The surface texture of the foils is similar to the bulk, with an additional (001) texture componentmore » that is oriented between the rolling and normal directions. Differences between the surface and bulk textures are expected to arise from shear forces during the rolling process and the influence that distinct strain histories have on subsequent texture evolution during recrystallization.« less

Identification of Possible Interstellar Dust Impact Craters on Stardust Foil I033N,1

NASA Astrophysics Data System (ADS)

Ansari, A.; ISPE Team; 29,000 Stardust@home Dusters

2011-12-01

The Interstellar Dust Collector onboard NASA's Stardust Mission - the first to return solid extraterrestrial material to Earth from beyond the Moon - was exposed to the interstellar dust stream for a total of 229 days prior to the spacecraft's return in 2006 [1]. Aluminum foils and aerogel tiles on the collector may have captured the first samples of contemporary interstellar dust. Interstellar Preliminary Examination (ISPE) focuses in part on crater identification and analysis of residue within the craters to determine the nature and origin of the impacting particles. Thus far, ISPE has focused on nine foils and found a total of 20 craters. The number density of impact craters on the foils exceeds by far estimates made from interstellar flux calculations [2]. To identify craters, foil I1033N,1 was scanned with the Field Museum's Evo 60 Scanning Electron Microscope (SEM) at a resolution of 52 nm/pixel with a 15 kV and 170-240 pA beam. Contamination was monitored according to the ISPE protocol: four 4 μm × 3 μm areas of C layers of different thicknesses on a Stardust-type Al foil were irradiated 20 times for 50 s each, while the C and Al signals were recorded with energy-dispersive X-ray spectroscopy (EDS). The C/Al ratio did not increase after 20 repetitions on each of the four areas. The same experiment repeated 7 months later yielded identical results. Thus, analysis with the SEM results in no detectable contamination. Crater candidates were manually selected from SEM images, then reimaged at higher resolution (17 nm/pixel) in order to eliminate false detections. The foil was then sent to Washington University for Auger Nanoprobe elemental analysis of crater 11_175 (diam. 1.1 μm), and to the Naval Research Laboratory for focused ion beam work and transmission electron microscopy and EDS. Twelve crater candidates (diam. 0.28 - 1.1 μm), both elliptical and circular, were identified. The number density of craters on foil 1033N is 15.8 cm^-2. Auger measurements

Long pulse Soft X-ray Emission from Laser Generated Irradiated Gold Foils

NASA Astrophysics Data System (ADS)

Davis, Joshua; Frank, Yechiel; Raicher, Erez; Fraenkel, Moshe; Keiter, Paul; Klein, Sallee; Drake, R. P.; Shvarts, Dov

2016-10-01

Long pulse soft x-ray sources (SXS) allow for flexibility in high-energy-density experimental designs by providing a means of driving matter to the high temperatures needed, for example to study radiation waves in different materials. SXSs can be made by using lasers to heat a high-Z thin foil, which then acts as a quasi-blackbody emitter. Previous studies of the x-ray emission characteristics of gold foils have focused on laser pulses of 1ns or less. We performed experiments using a 6.0ns laser pulse with energy of 2kJ on the Omega-60 system to generate and characterize multi-ns laser heated Au foils of thicknesses between 0.5-2.0 μm. We measured the 2D spatial profile of the emission with a soft x-ray camera and the time history of the emission with the Dante photodiode array . Effective temperatures for the emission were then calculated using the Dante measurements. Discussion of experimental results and a comparison with 1-D Rad-Hydro NLTE simulations will be presented.

Fabrication of full-color GaN-based light-emitting diodes on nearly lattice-matched flexible metal foils.

PubMed

Kim, Hyeryun; Ohta, Jitsuo; Ueno, Kohei; Kobayashi, Atsushi; Morita, Mari; Tokumoto, Yuki; Fujioka, Hiroshi

2017-05-18

GaN-based light-emitting diodes (LEDs) have been widely accepted as highly efficient solid-state light sources capable of replacing conventional incandescent and fluorescent lamps. However, their applications are limited to small devices because their fabrication process is expensive as it involves epitaxial growth of GaN by metal-organic chemical vapor deposition (MOCVD) on single crystalline sapphire wafers. If a low-cost epitaxial growth process such as sputtering on a metal foil can be used, it will be possible to fabricate large-area and flexible GaN-based light-emitting displays. Here we report preparation of GaN films on nearly lattice-matched flexible Hf foils using pulsed sputtering deposition (PSD) and demonstrate feasibility of fabricating full-color GaN-based LEDs. It was found that introduction of low-temperature (LT) grown layers suppressed the interfacial reaction between GaN and Hf, allowing the growth of high-quality GaN films on Hf foils. We fabricated blue, green, and red LEDs on Hf foils and confirmed their normal operation. The present results indicate that GaN films on Hf foils have potential applications in fabrication of future large-area flexible GaN-based optoelectronics.

Numerical study on the power extraction performance of a flapping foil with a flexible tail

NASA Astrophysics Data System (ADS)

Wu, J.; Shu, C.; Zhao, N.; Tian, F.-B.

2015-01-01

The numerical study on the power extraction performance of a flapping foil with a flexible tail is performed in this work. A NACA0015 airfoil is arranged in a two-dimensional laminar flow and imposed with a synchronous harmonic plunge and pitch rotary motion. A flat plate that is attached to the trailing edge of the foil is utilized to model a tail, and so they are viewed as a whole for the purpose of power extraction. In addition, the tail either is rigid or can deform due to the exerted hydrodynamic forces. To implement numerical simulations, an immersed boundary-lattice Boltzmann method is employed. At a Reynolds number of 1100 and the position of the pitching axis at third chord, the influences of the mass and flexibility of the tail as well as the frequency of motion on the power extraction are systematically examined. It is found that compared to the foil with a rigid tail, the efficiency of power extraction for the foil with a deformable tail can be improved. Based on the numerical analysis, it is indicated that the enhanced plunging component of the power extraction, which is caused by the increased lift force, directly contributes to the efficiency improvement. Since a flexible tail with medium and high masses is not beneficial to the efficiency improvement, a flexible tail with low mass together with high flexibility is recommended in the flapping foil based power extraction system.

Novel Procedure for Extraction of a Latent Grape Polyphenoloxidase Using Temperature-Induced Phase Separation in Triton X-114 1

PubMed Central

Sánchez-Ferrer, Alvaro; Bru, Roque; Garcia-Carmona, Francisco

1989-01-01

Polyphenoloxidase from grape berries is extracted only by nonionic detergents with a hydrophilic-lipophilic balance between 12.4 and 13.5. The enzyme was partially purified in latent form, free of phenolics and chlorophylls, by using temperature phase partitioning in a solution of Triton X-114. This method permits the purification of the enzyme with the same fold purification as the commonly used method, but with a yield three times higher and a 90% reduction in time needed. The latent enzyme can be activated by different treatments, including trypsin and cationic and anionic detergents. Cetyltrimethylamonium bromide was found to be the most effective detergent activator, followed by sodium dodecyl sulfate. Polyphenoloxidase in grape berries, in spite of being an integral membrane protein, had an anomalous interaction with Triton X-114, remaining in the detergent-poor phase after phase separation. This could be explained by its having a short hydrophobic tail that anchors it to the membrane. Images Figure 1 Figure 3 PMID:16667205

SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

NASA Technical Reports Server (NTRS)

Borg, J.; Horz, F.; Bridges, J. C.; Burchell, M. J.; Djouadi, Z.; Floss, C.; Graham, G. A.; Green, S. F.; Heck, P. R.; Hoppe, P.;

Handheld Reflective Foil Emissometer with 0.007 Absolute Accuracy at 0.05

NASA Astrophysics Data System (ADS)

van der Ham, E. W. M.; Ballico, M. J.

2014-07-01

The development and performance of a handheld emissometer for the measurement of the emissivity of highly reflective metallic foils used for the insulation of domestic and commercial buildings are described. Reflective roofing insulation based on a thin coating of metal on a more robust substrate is very widely used in hotter climates to reduce the radiant heat transfer between the ceiling and roof in commercial and residential buildings. The required normal emissivity of these foils is generally below 0.05, so stray reflected ambient infrared radiation (IR) makes traditional reflectance-based measurements of emissivity very difficult to achieve with the required accuracy. Many manufacturers apply additional coatings onto the metallic foil to reduce visible glare during installation on a roof, and to provide protection to the thin reflective layer; however, this layer can also substantially increase the IR emissivity. The system as developed at the National Measurement Institute, Australia (NMIA) is based on the principle of measurement of the modulation in thermal infrared radiation, as the sample is thermally modulated by hot and cold air streams. A commercial infrared to band radiation thermometer with a highly specialized stray and reflected radiation shroud attachment is used as the detector system, allowing for convenient handheld field measurements. The performance and accuracy of the system have been compared with NMIA's reference emissometer systems for a number of typical material samples, demonstrating its capability to measure the absolute thermal emissivity of these very highly reflective foils with an uncertainty of better than.

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PubMed Central

Pastoret, Marie-Hélène; Bühler, Julia; Weiger, Roland

2017-01-01

PURPOSE To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth. PMID:28874996

"Touching Triton": Building Student Understanding of Complex Disease Risk.

PubMed

Loftin, Madelene; East, Kelly; Hott, Adam; Lamb, Neil

2016-01-01

Life science classrooms often emphasize the exception to the rule when it comes to teaching genetics, focusing heavily on rare single-gene and Mendelian traits. By contrast, the vast majority of human traits and diseases are caused by more complicated interactions between genetic and environmental factors. Research indicates that students have a deterministic view of genetics, generalize Mendelian inheritance patterns to all traits, and have unrealistic expectations of genetic technologies. The challenge lies in how to help students analyze complex disease risk with a lack of curriculum materials. Providing open access to both content resources and an engaging storyline can be achieved using a "serious game" model. "Touching Triton" was developed as a serious game in which students are asked to analyze data from a medical record, family history, and genomic report in order to develop an overall lifetime risk estimate of six common, complex diseases. Evaluation of student performance shows significant learning gains in key content areas along with a high level of engagement.

Performance and Durability of High Temperature Foil Air Bearings for Oil-Free Turbomachinery

NASA Technical Reports Server (NTRS)

DellaCorte, C.; Lukaszewicz, V.; Valco, M. J.; Radil, K. C.; Heshmat, H.

2000-01-01

The performance and durability of advanced, high temperature foil air bearings are evaluated under a wide range (10-50 kPa) of loads at temperatures from 25 to 650 C. The bearings are made from uncoated nickel based superalloy foils. The foil surface experiences sliding contact with the shaft during initial start/stop operation. To reduce friction and wear, the solid lubricant coating, PS304, is applied to the shaft by plasma spraying. PS304 is a NiCr based Cr2O3 coating with silver and barium fluoride/calcium fluoride solid lubricant additions. The results show that the bearings provide lives well in excess of 30,000 cycles under all of the conditions tested. Several bearings exhibited lives in excess of 100,000 cycles. Wear is a linear function of the bearing load. The excellent performance measured in this study suggests that these bearings and the PS304 coating are well suited for advanced high temperature, oil-free turbomachinery applications.

Bi-Directional Ion Emission from Massive Gold Cluster Impacts on Nanometric Carbon Foils

PubMed Central

DeBord, J. Daniel; Della-Negra, Serge; Fernandez-Lima, Francisco A.; Verkhoturov, Stanislav V.; Schweikert, Emile A.

2012-01-01

Carbon cluster emission from thin carbon foils (5–40 nm) impacted by individual Aun+q cluster projectiles (95–125 qkeV, n/q = 3–200) reveals features regarding the energy deposition, projectile range, and projectile fate in matter as a function of the projectile characteristics. For the first time, the secondary ion emission from thin foils has been monitored simultaneously in both forward and backward emission directions. The projectile range and depth of emission were examined as a function of projectile size, energy, and target thickness. A key finding is that the massive cluster impact develops very differently from that of a small polyatomic projectile. The range of the 125 qkeV Au100q+q (q ≈ 4) projectile is estimated to be 20 nm (well beyond the range of an equal velocity Au+) and projectile disintegration occurs at the exit of even a 5 nm thick foil. PMID:22888385

Secret in the Margins: Rutherford's Gold Foil Experiment

ERIC Educational Resources Information Center

Aydin, Sevgi; Hanuscin, Deborah L.

2011-01-01

In this article, the authors describe a lesson that uses the 5E Learning Cycle to help students not only understand the atomic model but also how Ernest Rutherford helped develop it. The lesson uses Rutherford's gold foil experiment to focus on three aspects of the nature of science: the empirical nature of science, the tentativeness of scientific…

Use of Kelvin probe force microscopy for identification of CVD grown graphene flakes on copper foil

NASA Astrophysics Data System (ADS)

Kumar, Rakesh; Mehta, B. R.; Kanjilal, D.

2017-05-01

Graphene flakes have been grown by chemical vapour deposition (CVD) method on Cu foils. The obtained graphene flakes have been characterized by optical microscopy, field emission scanning electron microscopy, Kelvin probe force microscopy (KPFM) and Raman spectroscopy. The graphene flakes grown on Cu foil comprise mainly single layer graphene and confirm that the nucleation for graphene growth starts very quickly. Moreover, KPFM has been found to be a valuable technique to differentiate between covered and uncovered portion of Cu foil by graphene flakes deposited for shorter duration. The results show that KPFM can be a very useful technique in understanding the mechanism of graphene growth.

ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT: TRITON SYSTEMS, LLC SOLID BOWL CENTRIFUGE, MODEL TS-5000

EPA Science Inventory

Verification testing of the Triton Systems, LLC Solid Bowl Centrifuge Model TS-5000 (TS-5000) was conducted at the Lake Wheeler Road Field Laboratory Swine Educational Unit in Raleigh, North Carolina. The TS-5000 was 48" in diameter and 30" deep, with a bowl capacity of 16 ft3. ...

Visualization and Measurement of the Deflagration of JA2 Bonded to Various Metal Foils

DTIC Science & Technology

2016-01-01

Disclaimers The findings in this report are not to be construed as an official Department of the Army position unless so designated by other... design tools. There are numerous design parameters, including 1) the wires’ thermophysical properties and diameter(s), 2) their quantity, spacing, and...gasified by combustion. This is suggested by Figs. 7 and 8, which present posttest examinations of 2- and 3-mil-thick foils. On the 2-mil-thick Cu foils, a

A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst.

PubMed

Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

2016-07-08

Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe-Cr-Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1-3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 10(5) h(-1). The turnover frequency for the NO-CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading.

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

NASA Astrophysics Data System (ADS)

Zhao, Jie; Zhou, Guangmin; Yan, Kai; Xie, Jin; Li, Yuzhang; Liao, Lei; Jin, Yang; Liu, Kai; Hsu, Po-Chun; Wang, Jiangyan; Cheng, Hui-Ming; Cui, Yi

2017-10-01

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed LixM (M = Si, Sn, or Al) nanoparticles encapsulated by large graphene sheets. With the protection of graphene sheets, the large and freestanding LixM/graphene foils are stable in different air conditions. With fully expanded LixSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). This foil is also paired with high-capacity Li-free V2O5 and sulfur cathodes to achieve stable full-cell cycling.

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

DOE PAGES

Zhao, Jie; Zhou, Guangmin; Yan, Kai; ...

2017-07-10

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed Li xM (M = Si, Sn, or Al) nanoparticles encapsulated by largemore » graphene sheets. With the protection of graphene sheets, the large and freestanding Li xM/graphene foils are stable in different air conditions. With fully expanded Li xSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). As a result, this foil is also paired with high-capacity Li-free V 2O 5 and sulfur cathodes to achieve stable full-cell cycling.« less

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Jie; Zhou, Guangmin; Yan, Kai

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed Li xM (M = Si, Sn, or Al) nanoparticles encapsulated by largemore » graphene sheets. With the protection of graphene sheets, the large and freestanding Li xM/graphene foils are stable in different air conditions. With fully expanded Li xSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). As a result, this foil is also paired with high-capacity Li-free V 2O 5 and sulfur cathodes to achieve stable full-cell cycling.« less

[Implants with 32P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology].

PubMed

Assmann, Walter; Becker, Ricarda; Otto, Henrike; Bader, Markus; Clemente, Lucas; Reinhardt, Sabine; Schäfer, Claus; Schirra, Jörg; Uschold, Stephanie; Welzmüller, Andreas; Sroka, Ronald

2013-02-01

For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting (32)P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of (32)P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the (32)P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of (32)P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated (32)P-foils could extend essentially the application possibilities of LDR-brachytherapy. Copyright © 2012. Published by Elsevier GmbH.

Foil focusing of relativistic electron beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekdahl, Jr., Carl August

2017-10-26

When an intense relativistic electron beams (IREB) passes through a grounded metal foil, the transverse electric field due to the beam space charge is locally shorted out, and the beam is focused by the magnetic field of its current. The effect can be treated as focusing by a thin lens with first order aberration. Expressions for the focal length and aberration coefficient of the equivalent thin lens are developed in this note. These are then applied to practical examples representative of IREB research at Los Alamos National Laboratory.

Magnetohydrodynamic modelling of exploding foil initiators

NASA Astrophysics Data System (ADS)

Neal, William

2015-06-01

Magnetohydrodynamic (MHD) codes are currently being developed, and used, to predict the behaviour of electrically-driven flyer-plates. These codes are of particular interest to the design of exploding foil initiator (EFI) detonators but there is a distinct lack of comparison with high-fidelity experimental data. This study aims to compare a MHD code with a collection of temporally and spatially resolved diagnostics including PDV, dual-axis imaging and streak imaging. The results show the code's excellent representation of the flyer-plate launch and highlight features within the experiment that the model fails to capture.

Mass spectrometry-compatible silver staining of histones resolved on acetic acid-urea-Triton PAGE.

PubMed

Pramod, Khare Satyajeet; Bharat, Khade; Sanjay, Gupta

2009-05-01

Acetic acid-Urea-Triton (AUT) PAGE is commonly used method to separate histone variants and their post-translationally modified forms. Coomassie staining is the preferred method for protein visualization; however, its sensitivity is less than that of silver staining. Though silver staining of histones in AUT-PAGE has been reported, the method is time-consuming, dependent on prior staining by Amido black and has not been reported suitable for mass spectrometry. Here, we propose 'SDS-Silver' method for rapid, sensitive and mass spectrometry-compatible staining of histones resolved on AUT-PAGE.

SR-XRD and SR-FTIR study of the alteration of silver foils in medieval paintings.

PubMed

Salvadó, Nati; Butí, Salvador; Labrador, Ana; Cinque, Gianfelice; Emerich, Hermann; Pradell, Trinitat

2011-03-01

Altarpieces and polychrome carved wood from the fifteenth century AD usually exhibit golden and silvery areas by the application of a very thin foil of metal. The metal foils were normally protected from the atmosphere by a varnish or resin which maybe either preserved or absent. Moreover, they were glued to the background surface by adhesive substances (egg yolk, drying oil or animal glue). The high proportion of the glueing substances often renders the development of reaction compounds. With time, silver alters blacken or simply disappear completely. In this paper, we study the alterations to metal foils from a selection of fifteenth century artworks showing different glueing agents, organic coatings and several degrees of conservation of the organic coatings and metal leafs. The submillimetric layered structure and the high variability and low amount of most of the compounds present in the different layers, as well as their differing nature (organic and inorganic) make the use of micron-sensitive high-resolution techniques essential for their study. In particular, the high resolution, high brilliance and small footprint renders synchrotron radiation most adequate for their study. SR-XRD was performed to identify the reaction compounds formed in the different layers; μFTIR was used at to identify the silver protecting organic coatings, the metal foil glueing layers and the corresponding reaction compounds. The results obtained suggest that atmospheric corrosion is the dominant mechanism, and therefore that the degree of corrosion of the metal foils is mainly related to the conservation state of the protecting coatings.

Physical Constraints on the Ices present on Triton's Surface

NASA Astrophysics Data System (ADS)

Merlin, Frederic; Lellouch, Emmanuel; Quirico, Eric; Schmitt, Bernard

2017-10-01

Triton is the largest distant satellite of the solar system and was probably captured from the Transneptunian population by Neptune. It is mainly covered by N2 , CO, CO2 , CH4 and H2O in solid state and, except for H2O and CO2 , these species are also present in gas phase (with a thin N2 rich atmosphere, with CH4 and CO traces, see Lellouch et al., 2011, for instance). Sublimation and recondensation of the volatile species could lead to geographical and temporal variation, and could participate to the formation of complex chemical compounds formed from photochemistry occurring in the atmosphere (Krasnopolsky and Cruikshank, 1999) or from irradiation of N2 :CH4 :CO layers (Moore and Hudson, 2003).We present new analyses based on observations that have been performed in the near Infrared at the VLT-ESO with SINFONI from 2010 to 2013 at a spectral resolution ranging from 1500 to 4000, in order to give new constraints on the chemical and physical properties of the surface. Several models based on the Hapke theory (Hapke, 1993) have also been tested in order to constrain the abundance, the grain size and the state of the major ices (N2 , CH4 , CO, CO2 , H2O) as well as an attempt to identify other species. For this purpose, we use new optical constants of CO2 performed at 35 and 54K.We confirm the presence of deep N2 layers in which CO and CH4 are diluted. Our models highly support the presence of pure CH4 ice that can explain the enhancement of the CH4/N2 gas ratio in the atmosphere over what would be expected from ideal mixing. Our results also suggest significant smaller particles of CO2 and H2O than that reported in Quirico et al. (1999). H2O is expected to be present in its crystalline phase and CO2 spectral bands are compatible with a highly crystalline structure. Our models also suggest that CO2 is probably spread over a large area of the Triton surface. Our analyses do not support the presence of higher order hydrocarbons, such as those reported by Merlin (2015

System Being Developed to Measure the Rotordynamic Characteristics of Air Foil Bearings

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; DellaCorte, Christopher; Valco, Mark J.

2000-01-01

Because of the many possible advantages of oil-free engine operation, interest in using air lubricated foil-bearing technology in advanced oil-free engine concepts has recently increased. The Oil-Free Turbomachinery Program at the NASA Glenn Research Center at Lewis Field has partially driven this recent push for oil-free technology. The program's goal of developing an innovative, practical, oil-free gas turbine engine for aeropropulsion began with the development of NASA's high-temperature solid-lubricant coating, PS304. This coating virtually eliminates the life-limiting wear that occurs during the startup and shutdown of the bearings. With practically unlimited life, foil air bearings are now very attractive to rotating machinery designers for use in turbomachinery. Unfortunately, the current knowledge base of these types of bearings is limited. In particular, the understanding of how these types of bearings contribute to the rotordynamic stability of turbomachinery is insufficient for designers to design with confidence. Recent work in oil-free turbomachinery has concentrated on advancing the understanding of foil bearings. A high-temperature fiber-optic displacement probe system and measurement method were developed to study the effects of speed, load, temperature, and other environmental issues on the stiffness characteristics of air foil bearings. Since high temperature data are to be collected in future testing, the testing method was intentionally simplified to minimize the need for expensive test hardware. The method measures the displacement induced upon a bearing in response to an applied perturbation load. The early results of these studies, which are shown in the accompanying figure, indicate trends in steady state stiffness that suggest stiffness increases with load and decreases with speed. It can be seen, even from these data, that stiffness is not expected to change by orders of magnitude over the normal operating range of most turbomachinery; a

Interdigitated Eutectic Alloy Foil Anodes for Rechargeable Batteries

DOE PAGES

Kreder, III, Karl J.; Heligman, Brian T.; Manthiram, Arumugam

2017-09-19

An interdigitated eutectic alloy (IdEA) foil is presented as a framework for the development of alloy anodes with a capacity that is significantly higher than that of the traditional graphite/copper assembly. In conclusion, it is a simple, low-cost approach that can be applied to a broad range of alloy systems with various working ions such as Li, Na, or Mg.

Laser-induced structure formation on stretched polymer foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bityurin, Nikita; Arnold, Nikita; Baeuerle, Dieter

2007-04-15

Noncoherent structures that develop during UV laser ablation of stretched semicrystalline polymer foils are a very general phenomenon. A thermodynamic model based on stress relaxation within the modified layer of the polymer surface describes the main features of the observed phenomena, and, in particular, the dependence of the period of structures on laser wavelength, fluence, and number of laser pulses.

Evaluation of Defects inside Beryllium Foils using X-ray Computed Tomography and Shearing Interferometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakurai, Tatsuyuki; Kohmura, Yoshiki; Takeuchi, Akihisa

2007-01-19

When beryllium is used in transmission X-ray optical elements for spatially coherent beams, speckles are usually observed in the transmission images. These speckles seem to be caused by defects either inside or on the surface of beryllium foil. We measured highly polished beryllium foil using two methods, X-ray computed tomography and X-ray shearing interferometry. The results indicate that observed speckle pattern is caused by many voids inside beryllium or inner low-density regions.

3D Structure of the Inverse Karman Vortex Street in the Wake of a Flapping Foil

NASA Astrophysics Data System (ADS)

Bozkurttas, Meliha; Mittal, Rajat; Dong, Haibo

2004-11-01

Flapping foils are being considered for lift generation and/or propulsion in Micro Aerial Vehicles (MAVs) and Autonomous Underwater Vehicles (AUVs). In the present study, a DNS/LES solver that is capable of simulating these flows in all their complexity will be used. The flow around a NACA 0012 foil undergoing pitch oscillation at a chord Reynolds number of 12600 has been investigated and the comparison of mean thrust coefficient results with the experiment has indicated significant under-prediction of the thrust although good match is observed with a 2D RANS calculation. This discrepancy could be related to the absence of 3D effects in both numerical simulations. Although this conclusion has also been reached in other studies, the details of the physical mechanism that lead to inaccurate prediction of surface pressure and ultimately to thrust force for pitching and heaving flapping foils have not been clarified yet. In this study, the streamwise (secondary) vortical structures in the inverse Karman Vortex Street generated in the wake of a thrust producing flapping foil will be studied.

Development of damage suppression system using embedded SMA foil sensor and actuator

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Song, Dong Y.; Takeda, Nobuo

2000-06-01

The recent studies suggest possible applications of shape memory alloy (SMA) for a smart health monitoring and suppression of damage growth. The authors have been conducting research and development studies on applications of embedded SMA foil sensors and actuators in CFRP laminates. The goal of this research is suppression of damage growth in CFRP laminates. At first, the authors proposed a concept of damage suppression in CFRP laminates. Then, the development studies are conducted in three phases. The first phase is the improvement of interlaminar shear strength between SMA and CFRP laminates. Some surface treatments were investigated for the improvement of bonding property by peel resistance test and single lap shear strength test. The second phase is the investigation of fabrication technique for producing a CFRP panel with embedded SMA foils. Fixture jigs were devised to introduce tensile loads during the fabrication process. The third phase is the strength demonstration of CFRP laminates with embedded SMA foils. Some strength test were conducted to obtain the design data for aircraft structures. It is confirmed that the shrinking force of pre-strained SMA influences to the strength and the crack density of CFRP panel.

Triton X-114 based cloud point extraction: a thermoreversible approach for separation/concentration and dispersion of nanomaterials in the aqueous phase.

PubMed

Liu, Jing-fu; Liu, Rui; Yin, Yong-guang; Jiang, Gui-bin

2009-03-28

Capable of preserving the sizes and shapes of nanomaterials during the phase transferring, Triton X-114 based cloud point extraction provides a general, simple, and cost-effective route for reversible concentration/separation or dispersion of various nanomaterials in the aqueous phase.

Emittance growth due to multiple passes through H-minus stripping foil in Booster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardner, C. J.

Expressions for transverse emittance growth due to turn-by-turn passes through the H-minus stripping foil in Booster are developed here from simple principles of statistics and simple assumptions about the initial distribution of particles incident on the foil. These are meant to complement work already presented by Zeno [1, 2, 3] and Brown [4]. The expressions show that while the average emittance hEi of the distribution simply increases linearly with turn number, the emittance E based on the mean square particle position does so with an additional oscillatory term that depends on the machine tune. It is shown that this termmore » can be ignored as long as the turn number is su ciently large and the tune is su ciently far from integer and half-integer values. Under these conditions the relation between hEi and E is simply hEi = 2 E. This relation is shown to hold for a Gaussian distribution that is matched to the machine lattice. Two symmetry conditions which help characterize the particle distribution are identi ed. These provide justi cation for calling E an emittance. It is shown that if the conditions are satis ed by the initial distribution, they will not be satis ed after a single traversal of the foil and one turn around the machine. However, on subsequent turns the distribution can (and does) return to satisfying the conditions. Moreover, for su ciently large turn number, the symmetry conditions are approximately satis ed. As already noted in [4], the emittance growth per turn is proportional to the lattice beta at the foil and the mean square angular kick received by protons passing through the foil. We take the former to be 5 m. The latter is obtained from simulations performed with the code TRIM [5]. Having these numbers in hand, actual numbers for emittance growth are presented. The reader may wish to start with Section 11 and refer to previous sections as needed or desired.« less

Nonlinear Dynamics of a Foil Bearing Supported Rotor System: Simulation and Analysis

NASA Technical Reports Server (NTRS)

Li, Feng; Flowers, George T.

1996-01-01

Foil bearings provide noncontacting rotor support through a number of thin metal strips attached around the circumference of a stator and separated from the rotor by a fluid film. The resulting support stiffness is dominated by the characteristics of the foils and is a nonlinear function of the rotor deflection. The present study is concerned with characterizing this nonlinear effect and investigating its influence on rotordynamical behavior. A finite element model is developed for an existing bearing, the force versus deflection relation characterized, and the dynamics of a sample rotor system are studied. Some conclusions are discussed with regard to appropriate ranges of operation for such a system.

Cavitation Characteristics of a NACA 63-424 Hydrofoil and Performance Comparison with a Bidirectional Version of the Foil

NASA Astrophysics Data System (ADS)

Nedyalkov, Ivaylo; Wosnik, Martin

2012-11-01

A NACA 63-424 hydrofoil with a 75 mm chord and a 152 mm span was tested in the recently renovated 6-inch high-speed water tunnel at the University of New Hampshire. The NACA 63-424 foil is being considered for use on rotors of marine hydrokinetic turbines, including the US Department of Energy Reference Horizontal Axis Turbine (RHAT) for tidal and ocean current applications. For various angles of attack, the foil was tested at speeds ranging from 2 m/s to 12 m/s. Pressure in the test section was varied independently. For each angle, speed and pressure setting, high speed videos were recorded (at 3600 frames per second and above). Cavitation inception and desinance were obtained. Lift and drag were measured using a new 2-component force balance. In tidal turbines applications, bidirectional foils do not require pitch control, hence the experiments were repeated for a bidirectional version of the NACA 63-424 foil and the characteristics of the two foils were compared. The results can be used to predict cavitation inception and performance of marine hydrokinetic turbines, for a given site, deployment depth and and tip speed ratio.

Gas Foil Bearing Misalignment and Unbalance Effects

NASA Technical Reports Server (NTRS)

Howard, Samuel A.

2008-01-01

The effects of misalignment and unbalance on gas foil bearings are presented. The future of U.S. space exploration includes plans to conduct science missions aboard space vehicles, return humans to the Moon, and place humans on Mars. All of these endeavors are of long duration, and require high amounts of electrical power for propulsion, life support, mission operations, etc. One potential source of electrical power of sufficient magnitude and duration is a nuclear-fission-based system. The system architecture would consist of a nuclear reactor heat source with the resulting thermal energy converted to electrical energy through a dynamic power conversion and heat rejection system. Various types of power conversion systems can be utilized, but the Closed Brayton Cycle (CBC) turboalternator is one of the leading candidates. In the CBC, an inert gas heated by the reactor drives a turboalternator, rejects excess heat to space through a heat exchanger, and returns to the reactor in a closed loop configuration. The use of the CBC for space power and propulsion is described in more detail in the literature (Mason, 2003). In the CBC system just described, the process fluid is a high pressure inert gas such as argon, krypton, or a helium-xenon mixture. Due to the closed loop nature of the system and the associated potential for damage to components in the system, contamination of the working fluid is intolerable. Since a potential source of contamination is the lubricant used in conventional turbomachinery bearings, Gas Foil Bearings (GFB) have high potential for the rotor support system. GFBs are compliant, hydrodynamic journal and thrust bearings that use a gas, such as the CBC working fluid, as their lubricant. Thus, GFBs eliminate the possibility of contamination due to lubricant leaks into the closed loop system. Gas foil bearings are currently used in many commercial applications, both terrestrial and aerospace. Aircraft Air Cycle Machines (ACMs) and ground

SU-E-T-557: Measuring Neutron Activation of Cardiac Devices Irradiated During Proton Therapy Using Indium Foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avery, S; Christodouleas, J; Delaney, K

2014-06-01

Purpose: Measuring Neutron Activation of Cardiac devices Irradiated during Proton Therapy using Indium Foils Methods: The foils had dimensions of 25mm x 25mm x 1mm. After being activated, the foils were placed in a Canberra Industries well chamber utilizing a NaI(Tl) scintillation detector. The resulting gamma spectrum was acquired and analyzed using Genie 2000 spectroscopy software. One activation foil was placed over the upper, left chest of RANDO where a pacemaker would be. The rest of the foils were placed over the midline of the patient at different distances, providing a spatial distribution over the phantom. Using lasers and BBsmore » to align the patient, 200 MU square fields were delivered to various treatment sites: the brain, the pancreas, and the prostate. Each field was shot at least a day apart, giving more than enough time for activity of the foil to decay (t1=2 = 54.12 min). Results: The net counts (minus background) of the three aforementioned peaks were used for our measurements. These counts were adjusted to account for detector efficiency, relative photon yields from decay, and the natural abundance of 115-In. The average neutron flux for the closed multi-leaf collimator irradiation was measured to be 1.62 x 106 - 0.18 x 106 cm2 s-1. An order of magnitude estimate of the flux for neutrons up to 1 keV from Diffenderfer et al. gives 3 x 106 cm2 s-1 which does agree on the order of magnitude. Conclusion: Lower energy neutrons have higher interaction cross-sections and are more likely to damage pacemakers. The thermal/slow neutron component may be enough to estimate the overall risk. The true test of the applicability of activation foils is whether or not measurements are capable of predicting cardiac device malfunction. For that, additional studies are needed to provide clinical evidence one way or the other.« less

Using Aluminum Foil to Record Structures in Sedimentary Rock.

ERIC Educational Resources Information Center

Metz, Robert

1982-01-01

Aluminum foil can be used to make impressions of structures preserved in sedimentary rock. The impressions can be projected onto a screen, photographed, or a Plaster of Paris model can be made from them. Impressions of ripple marks, mudcracks, and raindrop impressions are provided in photographs illustrating the technique. (Author/JN)

Focused Ion Beam Recovery of Hypervelocity Impact Residue in Experimental Craters on Metallic Foils

NASA Technical Reports Server (NTRS)

Graham, G. A.; Teslich, N.; Dai, Z. R.; Bradley, J. P.; Kearsley, A. T.; Horz, F.

2006-01-01

The Stardust sample return capsule will return to Earth in January 2006 with primitive debris collected from Comet 81P/Wild-2 during the fly-by encounter in 2004. In addition to the cometary particles embedded in low-density silica aerogel, there will be microcraters preserved in the Al foils (1100 series; 100 micrometers thick) that are wrapped around the sample tray assembly. Soda lime spheres (approximately 49 m in diameter) have been accelerated with a light-gas-gun into flight-grade Al foils at 6.35 km s(sup -1) to simulate the potential capture of cometary debris. The preserved crater penetrations have been analyzed using scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDX) to locate and characterize remnants of the projectile material remaining within the craters. In addition, ion beam induced secondary electron imaging has proven particularly useful in identifying areas within the craters that contain residue material. Finally, high-precision focused ion beam (FIB) milling has been used to isolate and then extract an individual melt residue droplet from the interior wall of an impact penetration. This enabled further detailed elemental characterization, free from the background contamination of the Al foil substrate. The ability to recover pure melt residues using FIB will significantly extend the interpretations of the residue chemistry preserved in the Al foils returned by Stardust.

Spanwise visualization of the flow around a three-dimensional foil with leading edge protuberances

NASA Astrophysics Data System (ADS)

Stanway, M. J.; Techet, A. H.

2006-11-01

Studies of model humpback whale fins have shown that leading edge protuberances, or tubercles, can lead to delayed stall and increased lift at higher angles of attack, compared to foils with geometrically smooth leading edges. Such enhanced performance characteristics could prove highly useful in underwater vehicles such as gliders or long range AUVs (autonomous underwater vehicles). In this work, Particle Imaging Velocimetry (PIV) is performed on two static wings in a water tunnel over a range of angles of attack. These three- dimensional, finite-aspect ratio wings are modeled after a humpback whale flipper and are identical in shape, tapered from root to tip, except for the leading edge. In one of the foils the leading edge is smooth, whereas in the other, regularly spaced leading edge bumps are machined to simulate the whale’s fin tubercles. Results from these PIV tests reveal distinct cells where coherent flow structures are destroyed as a result of the leading edge perturbations. Tests are performed at Reynolds numbers Re ˜ O(10^5), based on chordlength, in a recirculating water tunnel. An inline six-axis load cell is mounted to measure the forces on the foil over a range of static pitch angles. It is hypothesized that this spanwise breakup of coherent vortical structures is responsible for the delayed angle of stall. These quantitative experiments complement exiting qualitative studies with two dimensional foils.

Development of long-lived thick carbon stripper foils for high energy heavy ion accelerators by a heavy ion beam sputtering method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muto, Hideshi; Ohshiro, Yukimitsu; Kawasaki, Katsunori

2013-04-19

In the past decade, we have developed extremely long-lived carbon stripper foils of 1-50 {mu}g/cm{sup 2} thickness prepared by a heavy ion beam sputtering method. These foils were mainly used for low energy heavy ion beams. Recently, high energy negative Hydrogen and heavy ion accelerators have started to use carbon stripper foils of over 100 {mu}g/cm{sup 2} in thickness. However, the heavy ion beam sputtering method was unsuccessful in production of foils thicker than about 50 {mu}g/cm{sup 2} because of the collapse of carbon particle build-up from substrates during the sputtering process. The reproduction probability of the foils was lessmore » than 25%, and most of them had surface defects. However, these defects were successfully eliminated by introducing higher beam energies of sputtering ions and a substrate heater during the sputtering process. In this report we describe a highly reproducible method for making thick carbon stripper foils by a heavy ion beam sputtering with a Krypton ion beam.« less

In situ calibration of the foil detector for an infrared imaging video bolometer using a carbon evaporation technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mukai, K., E-mail: mukai.kiyofumi@LHD.nifs.ac.jp; Peterson, B. J.; SOKENDAI

The InfraRed imaging Video Bolometer (IRVB) is a useful diagnostic for the multi-dimensional measurement of plasma radiation profiles. For the application of IRVB measurement to the neutron environment in fusion plasma devices such as the Large Helical Device (LHD), in situ calibration of the thermal characteristics of the foil detector is required. Laser irradiation tests of sample foils show that the reproducibility and uniformity of the carbon coating for the foil were improved using a vacuum evaporation method. Also, the principle of the in situ calibration system was justified.

Effect of bromine-dopant on radiation-driven Rayleigh-Taylor instability in plastic foil

NASA Astrophysics Data System (ADS)

Xu, Binbin; Ma, Yanyun; Yang, Xiaohu; Tang, Wenhui; Ge, Zheyi; Zhao, Yuan; Ke, Yanzhao; Kawata, Shiego

2017-10-01

Effects of bromine (Br) dopant on the growth of radiation-driven ablative Rayleigh-Taylor instability (RTI) in plastic foils are studied by radiation hydrodynamics simulations and theoretical analysis. It is found that the Br-dopant in plastic foil reduces the seed of ablative RTI. The main reasons of the reduction are attributed to the smaller oscillation amplitude of ablative Richtmyer-Meshkov instability (RMI) induced by the smaller post-shock sound speed, and the smaller oscillation frequency of ablative RMI induced by the smaller ablation velocity and blow-off plasma velocity. The Br-dopant also decreases the linear growth rate of ablative RTI due to the smaller acceleration. Treating the perturbation growth as a function of foil’s displacement, the perturbation growth would increase in Br-doped foil at the phase of ablative RTI, which is attributed to the decrease of the ablation velocity and the density gradient scale length. The results are helpful for further understanding the influence of high-Z dopant on the radiation-driven ablative RTI.

Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

DOE PAGES

Hooper, R. J.; Davis, C. G.; Johns, P. M.; ...

2015-06-26

Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical modelmore » for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.« less

Evidence for Coincident Fusion Products Using Silicon Surface-barrier Detectors

NASA Astrophysics Data System (ADS)

Jones, Steven; Scott, Mark; Keeney, Frank

2002-10-01

We report experimental results showing coincident proton and triton production from the reaction: d + d --> t (1.01 MeV) + p (3.02 MeV). Partially-deuterided thin titanium foils were positioned between two silicon surface-barrier detectors which were mounted in a small cylindrical vacuum chamber which also served as a Faraday cage. We performed Monte Carlo studies using the SRIM code to determine the expected energies of arriving particles after they exit the host foil. The dual-coincidence requirement reduces background to very low levels so that low yields from very thin TiD foils can be readily detected. In one sequence of experiments, we observed 74 foreground coincidences in the regions of interest compared with 24 background counts; the statistical significance is approximately ten standard deviations. A striking advance is that the repeatability from the dual-coincidence experiments is currently greater than 70%.

Study of Electric Explosion of Flat Micron-Thick Foils at Current Densities of (5-50)×108 A/cm2

NASA Astrophysics Data System (ADS)

Shelkovenko, T. A.; Pikuz, S. A.; Tilikin, I. N.; Mingaleev, A. R.; Atoyan, L.; Hammer, D. A.

2018-02-01

Electric explosions of flat Al, Ti, Ni, Cu, and Ta foils with thicknesses of 1-16 μm, widths of 1-8 mm, and lengths of 5-11 mm were studied experimentally on the BIN, XP, and COBRA high-current generators at currents of 40-1000 kA and current densities of (5-50) × 108 A/cm2. The images of the exploded foils were taken at different angles to the foil surface by using point projection radiography with an X-pinch hot spot as the radiation source, the spatial resolution and exposure time being 3 μm and 50 ps, respectively, as well by the laser probing method with a spatial resolution of 20 μm and an exposure time of 180 ps. In the course of foil explosion, rapidly expanding objects resembling the core and corona of an exploded wire were observed. It is shown that the core of the exploded foil has a complicated time-varying structure.

Experimental evidence of beam-foil plasma creation during ion-solid interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Prashant, E-mail: prashant@iuac.res.in; Nandi, Tapan

2016-08-15

Charge state evolution of the energetic projectile ions during the passage through thin carbon foils has been revisited using the X-ray spectroscopy technique. Contributions from the bulk and the solid surface in the charge changing processes have been segregated by measuring the charge state distribution of the projectile ions in the bulk of the target during the ion–solid interaction. Interestingly, the charge state distribution measured in the bulk exhibits Lorentzian profile in contrast to the well-known Gaussian structure observed using the electromagnetic methods and the theoretical predictions. The occurrence of such behavior is a direct consequence of the imbalance betweenmore » charge changing processes, which has been seen in various cases of the laboratory plasma. It suggests that the ion-solid collisions constitute high-density, localized plasma in the bulk of the solid target, called the beam-foil plasma. This condensed beam-foil plasma is similar to the high-density solar and stellar plasma which may have practical implementations in various fields, in particular, plasma physics and nuclear astrophysics. The present work suggests further modification in the theoretical charge state distribution calculations by incorporating the plasma coupling effects during the ion–solid interactions. Moreover, the multi-electron capture from the target exit surface has been confirmed through comparison between experimentally measured and theoretically predicted values of the mean charge state of the projectile ions.« less

Purification and Identification of Membrane Proteins from Urinary Extracellular Vesicles using Triton X-114 Phase Partitioning.

PubMed